Molecules to Materials Common Misconceptions

M8 MA Curriculum v. 3.2 Unit 1 – ©2018 KnowAtomTM

Molecules to Materials At-a-Glance:

In the eighth grade, students connect scientific concepts with real-world applications, focusing on how science and engineering influence the natural

world and society. In this unit, students are introduced to matter and energy as they learn about how scientists and engineers design materials with

specific properties to address a wide range of societal needs. They focus on the basic structure of matter,

and how energy changes matter in physical and chemical changes. They then use that knowledge to

analyze how materials are turned into products with specific properties through manufacturing processes.

Common Misconceptions: Misconception: Mass is not conserved

if a gas is produced during a chemical reaction. Fact: Mass is always conserved. In

an open system, we can’t measure the gas that’s produced, but that doesn’t mean it’s not there.

Misconception: Manufacturing is old-fashioned and doesn’t address current societal needs. Fact: Manufacturing plays an

important role in the development of the majority of products we use in our everyday lives.

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A Breakdown of the Lesson Progression:

Polymer Structure and Function Students use the phenomenon of why some sports balls bounce higher than others to investigate how the amount of reactants can influence the properties of the products in a chemical reaction. They connect the molecular structure of a polymer bouncy ball with its property of bounciness.

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Chemical Reactions Students use the phenomenon of how concrete is made to support their analysis of how chemical reactions produce new substances with different properties.

Using a Scientific Process In this brief intro lesson, students discuss why certain materials are useful for a particular function and how scientists ask questions and follow a process to get evidence-based answers to those questions.

Intro

Manufacturing Processes

Students connect what they know about chemical reactions and the matter that makes up materials to how materials come together to form finished products through manufacturing. They model a basic manufacturing process to create plastic keychains for a factory, and then make improvements to the manufacturing process to decrease waste and improve efficiency and output.


Unit 1: Molecules to Materials

Table of Contents Curriculum

Unit Overview Applying Massachusetts STE Standards Science and Engineering Practices Unit 1 Pacing Guide Example Science Words to Know Teacher Background Borax and Potassium Iodide Safety Overview Vocabulary Assessment Concept Assessment

4 5 9 13 15 18 40 96 98

Lessons Intro Lesson: Using a Scientific Process 41 Lesson 1: Chemical Reactions Lesson 2: Polymer Structure and Function

Facilitated Set-Up Procedure Blank Data Table and Blank Graph

Lesson 3: Manufacturing Processes

48 62 82 83 84

Appendices Assessment Answer Keys Lab Manual Answer Key Common Core Connections Sample Concept Map Support for Differentiated Instruction Materials Chart

107 112 115 119 120 123


On a cold December day, an engineering student named Elliot Hawkes acted like a slow-motion Spiderman, inching his way up a glass wall behind his science lab. He was able to stick to the glass because he was testing a new kind of material that was attached to his hands and feet. Researchers like Hawkes are interested in creating materials that have unique sets of properties that will allow them to be used in a particular way. These researchers work in the field of materials science, focused on the relationship between the structure and the properties of different materials. Materials scientists are constantly looking for ways to make new materials perform better to meet society’s needs. In this unit, students explore the relationship between matter’s structure and its function, and how people can use this knowledge to manufacture new materials and products with specific purposes. Students begin by investigating how matter is changed, but always conserved, in both endothermic and exothermic reactions. They then apply what they’ve learned to manipulate the properties of a product by changing the amounts of reactants in a chemical reaction. Students end by using a manufacturing process to turn raw materials into a finished product (plastic keychains). 1. Describe how atoms and molecules make up all of the matter in the world. 2. Analyze the properties of substances before and after they interact to determine whether a chemical reaction has occurred. 3. Describe how new materials and products are produced using manufacturing processes to ensure quality and safety.

Overview:

Unit Goals:

Unit 1:

Molecules to Materials


Applying Massachusetts Science and Technology/Engineering (STE) Standards:

This unit covers the following Massachusetts STE Standards. Each standard includes where it is found in the unit, as well as how it applies the relevant disciplinary core ideas (listed in orange). *Note: Science and engineering practices are listed separately because many of the practices are incorporated into every lesson.

Grade-Specific Standards:

MS-PS1 Matter and Its Interactions 8. MS-PS1-1. 8. MS-PS1-2.

Develop a model to describe that (a) atoms combine in a multitude of ways to produce pure substances which make up all of the living and nonliving things that we encounter, (b) atoms form molecules and compounds that range in size from two to thousands of atoms, and (c) mixtures are composed of different proportions of pure substances. * In this unit, students use but do not develop models of simple molecules and extended structures. Structure and Properties of Matter: In Lesson 1, students

analyze the structural composition of different kinds of matter, evaluating how molecules are formed and rearranged in chemical reactions.

In Lesson 2, students focus on the structure and properties of polymers, which are large molecules made up of hundreds or thousands of smaller molecules.

Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred. Structure and Properties of Matter: In Lesson 1, students

use the phenomenon of how concrete is made to connect the structure of a substance with its properties.

In Lesson 2, students combine two substances to create a polymer, comparing the properties of the substances before and after they combine.


Chemical Reactions: In Lesson 1, students analyze their data to determine if a reaction occurred, supporting their analysis with a description of what happened at the molecular level to result in the different properties of the reactants and products.

In Lesson 2, students manipulate the amount of reactants to produce a desired property (bounciness).

MS-PS1 Matter and Its Interactions 8. MS-PS1-4. 8. MS-PS1-5.

Develop a model that describes and predicts changes in particle motion, relative spatial arrangement, temperature, and state of a pure substance when thermal energy is added or removed. * In this unit, students use but do not develop models to describe and predict changes in particle motion when thermal energy is added or removed. Definitions of Energy: Students are introduced to the

relationship between a substance’s temperature, its particle motion, and the amount of thermal energy present. Lesson 1

Use a model to explain that atoms are rearranged during a chemical reaction to form new substances with new properties. Explain that the atoms present in the reactants are all present in the products and thus the total number of atoms is conserved. Chemical Reactions: Students develop a visual model that

describes how mass is conserved in a chemical reaction, labeling relationships between the different parts. Lesson 1

MS-ETS2 Materials, Tools, and Manufacturing 8. MS-ETS2-4 (MA).

Use informational text to illustrate that materials maintain their composition under various kinds of physical processing; however, some material properties may change if a process changes the particulate structure of a material. Structure and Properties of Matter: Students describe how

people can modify materials with both physical and chemical processing, using what they know about physical and chemical changes to support their analysis. Lesson 3


MS-ETS2 Materials, Tools, and Manufacturing 8. MS-ETS2-5 (MA).

Present information that illustrates how a product can be created using basic processes in manufacturing systems, including forming, separating, conditioning, assembling, finishing, quality control, and safety. Compare the advantages and disadvantages of human vs. computer control of these processes. Chemical Reactions: Students model a basic manufacturing

process to create plastic keychains for a factory, and discuss human vs. computer control of these processes. Lesson3


Supporting Standards:

MS-PS3 Energy 6. MS-PS1-6.

Plan and conduct an experiment using exothermic and endothermic reactions to explain that the type and concentration of the reacting substances affects the amount of thermal energy released or absorbed. Chemical Reactions: Students carry out an investigation

to compare an endothermic and an exothermic reaction, observing and describing how energy is transferred in each reaction depending on the reacting substances. Lesson 1

MS-PS3 Energy 7. MS-PS3-5. 7. MS-PS3-7 (MA).

Present evidence to support the claim that when the kinetic energy of an object changes, energy is transferred to or from the object. Conservation of Energy and Energy Transfer: In

Lesson 1, students analyze how energy transfers between a chemical reaction and the environment, connecting that transfer of energy with a change in temperature.

In Lesson 2, students connect what they have learned about energy transfer with the structure and properties of matter as they manipulate a chemical reaction to change the bounce height of a bouncy ball polymer.

Use informational text to describe the relationship between kinetic and potential energy and illustrate conversions from one form to another. Structure and Properties of Matter: Students are

introduced to potential and kinetic energy, focusing in this unit on chemical potential energy and thermal energy. Lesson 1


Science and Engineering Practices

Students use the following science and engineering practices in the unit’s lessons.

Lesson 1: Chemical Reactions 1. Asking questions (for science) and defining problems (for engineering) Throughout the lesson, students ask questions to clarify or seek additional

information as they analyze the properties of several substances before and after they react.

Students investigate the question: “How can you tell if a chemical reaction has taken place when two or more substances combine?”

2. Developing and using models Students develop a visual model that shows how mass is conserved in a

chemical reaction, labeling any relationships they notice between the different parts of their model. Students use their models and the results from the investigation to help them make sense of their initial claim.

3. Planning and carrying out investigations Students collaboratively carry out an investigation into endothermic and

exothermic reactions, exploring how thermal energy is either released or absorbed when vinegar and baking soda combine, and then when hydrogen peroxide and potassium iodide combine. They compare the temperature change and properties of the reactants and products.

4. Analyzing and interpreting data Students collect and analyze data on the temperatures and observable

properties of two different solutions before and after the substances are combined to determine whether a chemical reaction took place and if that reaction was exothermic or endothermic.

6. Constructing explanations (for science) and designing solutions (for engineering) Students use their temperature data and observations to support their

explanation about whether or not a chemical reaction occurred, whether it was endothermic or exothermic, and whether mass was conserved.

7. Engaging in argument from evidence Students construct and present their team’s conclusion to the class, using

their data to support their argument about how the structure of matter changes during a chemical reaction, resulting in new and different properties of the product without creating or destroying mass in the process.


They respectfully provide and receive critiques about their analysis, posing and responding to their peers’ questions.

8. Obtaining, evaluating, and communicating information Students critically read their lab manuals to determine the central ideas,

which they communicate in the reading and Socratic dialogue. Students communicate within their teams as they collect and evaluate

their data from the investigation. After the investigation, students come together as a class to communicate

their team’s results in writing and orally in the wrap-up.

Lesson 2: Polymer Structure and Function 1. Asking questions (for science) and defining problems (for engineering) Students ask questions during the Socratic dialogue to clarify or seek

additional information. They develop a question that will help guide them through an experiment

into the relationship between the amount of sodium borate (borax) used to create a polymer bouncy ball and the polymer’s bounce height.

They ask questions to determine relationships between the independent and dependent variables in their experiment.

During the wrap-up, students ask questions that arise from their observations of their models, their data, or any unexpected results.

2. Developing and using models Students create a visual model (scientific diagram) of their polymer bouncy

ball system. Students use the model to visualize how the materials will be used, and to communicate their experiment to others.

They then create a physical model to investigate how changing the amount of the sodium borate (borax) used to create a polymer bouncy ball affects the polymer’s bounce height.

3. Planning and carrying out investigations Student teams collaboratively develop a plan to test their polymer bouncy

balls, comparing the bounce height of two polymers, made with different amounts of sodium borate (borax), for five separate trials when dropped from the same height above the ground.

4. Analyzing and interpreting data Students collect and analyze data on the rebound height of the bouncy ball

polymer when it is made with 1 gram of borax compared to 5 grams, looking for patterns that might indicate a relationship between the amount of borax used and the rebound height of the bouncy ball.


5. Using mathematics and computational thinking Students conduct five trials, recording the rebound height of both bouncy

ball polymers, then calculating the average rebound height. Students then graph their data to help them identify patterns.

6. Constructing explanations (for science) and designing solutions (for engineering) Students use the data they gathered in the experiment to construct an

explanation (conclusion) that either supports or rejects their hypothesis about how the quantity of the sodium borate (borax) used affects the polymer’s bounce height.

7. Engaging in argument from evidence Students construct and present their team’s conclusion to the class, using

their data from the experiment to support their argument about the relationship between the amount of sodium borate (borax) used and the polymer’s bounce height.



which they communicate in the reading and Socratic dialogue portions of the lesson.

Students communicate within their teams as they carry out the experiment, collecting and evaluating their data.

After the experiment, students come together as a class to communicate their team’s results in writing and orally in the wrap-up.


Lesson 3: Manufacturing Processes 2. Developing and using models Students model a basic manufacturing process to create plastic keychains

for a factory, and then make improvements to the manufacturing process to decrease waste and improve efficiency and output.

3. Planning and carrying out investigations Students carry out an investigation in which they set up an assembly line

formation within their team to organize the flow of materials through each step of the manufacturing process.

4. Analyzing and interpreting data Students collect and analyze quality control data, analyzing how many

keychains were attempted, how many were completed, the total time to complete one batch of keychains, and the average time to complete one keychain. Students also measure the total mass of batch waste.

5. Using mathematics and computational thinking Students collect data for one batch, analyze it, and then try to improve their

process to decrease waste and improve efficiency and output. 6. Constructing explanations (for science) and designing solutions (for engineering) Students compare their quality control data in the original process to the

data from the improved process to determine how their changes positively or negatively impacted the average time it took to produce each keychain, the amount of waste produced, and the quality of the keychains compared to Batch 1.

7. Engaging in argument from evidence Students come together as a class to compare team results, engaging in

argument about which changes had the most positive and/or negative effects on the efficiency, output, and waste production.



which they communicate in the reading and Socratic dialogue portions of the lesson.

Students communicate within their teams as they carry out the manufacturing process, collecting and evaluating their data.

After the investigation, students come together as a class to communicate their team’s results in writing and orally in the wrap-up.

* Unit connections to Common Core Math practices: MP.2, MP.3, MP.4, MP.5, and MP. 6.


Unit 1 Pacing Guide Example

All KnowAtom units are designed to take approximately one month. Lessons may span one or two weeks. This pacing guide provides one example for how to break down the lessons in this unit over a month. Breakdown in this guide is based on 45- to 55-minute class periods. Communities that have longer or shorter class periods or schedules where science class occurs more frequently can modify this guide accordingly. Any days in this guide that appear unused take into account months with holidays, vacations, times when a lab and/or investigation takes longer to complete. Note that at the beginning of the school year, when the engineering and scientific processes are new to students, labs may take longer to complete.

Unit 1: Molecules to Materials

Week 1 Intro Lesson

Start: As a class, read the Intro section of the KnowAtom student lab manual. Final Goal: Students set-up their laboratory notebooks.

Lesson 1 Start: As a class, read Section 1 of the KnowAtom student lab manual. Final Goal: Transition to the Socratic dialogue.

Lesson 1 Start: Socratic dialogue. Final Goal: Transition to lesson phenomena and investigation.

Lesson 1 Start: Students explore lesson phenomena and carry out the chemical reactions portion of the investigation. Final Goal: Students collect reaction data.

Lesson 1 Start: Students analyze the substances and develop and use a model for the investigation. Final Goal: Students complete the visual model for the investigation.

Week 2 Lesson 1

Start: As a class, review investigation results and analysis. Final Goal: Wrap-up the investigation and debrief.


Lesson 2 Start: Socratic dialogue Final Goal: Transition to lesson phenomena and Lab 1 question.

Lesson 2 Start: Students explore lesson phenomena and develop Lab 1 question. Final Goal: Students develop lab question, research and hypothesis with check-ins.

Lesson 2 Start: Teams complete lab development and may begin experiment. Final Goal: Students create Polymer 1 and Polymer 2.


Day 1 Day 2 Day 3 Day 4 Day 5 Week 3

Lesson 2 Start: Teams collect data for Polymer 1 and Polymer 2. Final Goal: Teams analyze their experiment data and evaluate results.

Lesson 2 Start: As a class, review lab conclusions and wrap up the lab. Final Goal: Lesson wrap-up and debrief.

Non-Science Day

Non-Science Day


Week 4 Lesson 3

Start: Socratic dialogue. Final Goal: Transition to the Manufacturing Process Activity.

Lesson 3 Start: Teams carry out ABC Factory’s keychain manufacturing process. Final Goal: Teams complete the analysis portion of the manufacturing process.

Lesson 3 Start: Teams carry out their revised ABC Factory’s keychain manufacturing process. Final Goal: Teams complete the analysis portion of their revised manufacturing process.

Lesson 3 Start: As a class, wrap up the investigation and debrief. Final Goal: Review assigned assessment questions (optional).

Non-Science Day


This unit’s vocabulary is divided into an intro lesson and 3 main lessons. Use a blank concept map visual to connect vocabulary once the unit is complete. An example concept map is displayed in Appendix 3. Intro Lesson 1. cause and effect – a relationship between events or things,

where one is the result of the other 2. data – the measurements and observations gathered from an

experiment 3. experiment – a specific procedure that tests if a hypothesis

is true, false, or inconclusive 4. function – the normal action of something or how something

works 5. materials – substances that are designed to be used for

certain applications 6. pattern – something that happens in a regular and repeated

way 7. process – any series of steps designed to meet a goal 8. property – an observable or measurable characteristic of a

substance 9. science – all knowledge gained from experiments 10. scientist – a person who follows a scientific process to

discover new knowledge 11. structure – the way in which parts are put together to form

a whole

Science Words to Know:


12. synthetic – formed through a chemical process developed by humans, as opposed to those of natural origin

Lesson 1 13. atom – the smallest piece of matter that has the

properties of an element; a combination of three subatomic particles: protons, neutrons, and electrons

14. chemical change – a change that rearranges the chemical

structure of a substance through a chemical reaction 15. chemical reaction – a process that rearranges the atoms

of the original substance into a new substance that has different properties from the original substances

16. chemical energy – a form of potential energy that is

stored in the bonds holding together atoms and molecules 17. element – a substance made up entirely of one kind of

atom 18. energy – the ability to do work 19. endothermic – a process that absorbs energy from the

environment 20. exothermic– a process that releases energy into the

environment 21. kinetic energy – the energy of motion 22. mass – a measure of the amount of matter that makes up

an object or substance; measured in grams (g) 23. matter – everything that has mass and takes up space 24. molecule – a combination of two or more atoms bonded

together


25. physical change – a change that does not affect the

chemical structure of a substance 26. potential energy – energy that is stored 27. scale – the size, extent, or importance (magnitude) of

something relative to something else 28. system – a set of connected, interacting parts that form a

more complex whole 29. thermal energy – the motion of atoms and molecules in

a substance or object as its temperature increases Lesson 2 30. polymer – a large molecule made up of many smaller

molecules bonded together in a repeating chainlike pattern

Lesson 3 31. manufacturing – the operation of transforming raw

materials into a finished product 32. raw material – a basic material from which a product is

made


Teacher Background

Elliot Hawkes scaled a glass wall using an adhesive material that mimicked the structure of gecko feet. Materials are substances that are designed to be used for certain applications, and they can be natural or synthetic (formed through a chemical process developed by humans, as opposed to those of natural origin). Researchers have long been interested in geckos because they have a remarkable ability to stick to almost any surface they walk on. They can run up smooth vertical walls and across the ceiling without falling. This “stickability,” also called adhesiveness, is a property that gecko feet, glue, and tape all share. A property is a measurable or observable characteristic of a substance. Geckos are able to stick to most surfaces because their feet are lined with millions of tiny hairs, called setae, that create an attraction between the gecko’s feet and the surface. Unlike adhesives such as glue or tape, however, the gecko’s sticky feet can attach and detach from the surface easily. This means the adhesiveness doesn’t have to be permanent, like glue. Because of these adhesive properties, researchers have been using the structure of the gecko foot to develop innovative adhesive materials to be used in a wide range of

industries, including healthcare, sport, defense, and nanotechnology. Researchers who design novel materials are part of the STEM cycle. STEM stands for science, technology, engineering, and math. All knowledge learned from experiments is part of science. Engineers apply

scientific knowledge to create new technologies that solve problems. Math is a tool that both scientists and engineers use to capture results and communicate those results to others.

Mimicking Nature to Design Materials

© Bjørn Christian Tørrissen

close-up of a gecko’s foot


Anyone who follows a scientific process to discover new knowledge is a scientist. A process is any series of steps designed to meet a goal. Scientists use a scientific process to guide them in developing a replicable experiment as they seek out answers to questions about the world around them. There are eight steps that scientists often follow to answer questions using data from experiments. These steps provide scientists with a logical framework to go about answering their questions. 1. All scientific investigations start with a question—a statement that requires an answer. The question ends in a question mark and does not include words like “I” or “because.” One question that scientists interested in the gecko’s ability to stick to different surfaces might want to answer is: “How does the number of setae (hairs) on a gecko’s feet affect its adhesiveness?” 2. After formulating a question, scientists do background research on their topic. Research is the search for knowledge across books, experts, websites, and other reliable sources. While researching, scientists learn what other experiments have been done on their topic of interest and what else needs to be known. 3. Based on their research, scientists create a hypothesis about the question they are asking. A hypothesis, or claim, is a clear and concise statement that can be proved true or false. The sentence does not include personal pronoun words like “my” or “I think.” Hypotheses are written as declarative sentences, such as: “More setae on a gecko’s feet increase the gecko’s adhesiveness,” or “Fewer setae on a gecko’s feet increase the gecko’s adhesiveness.”

Question Research Hypothesis Summarize Experiment

Materials and

Procedure Scientific Diagram Data Conclusion

Following a Scientific Process


4. Next, scientists summarize the experiment that will test their hypothesis by briefly describing the controlled testing and data needed to prove the hypothesis true or false. An experiment is a specific procedure that tests if a hypothesis is true, false, or inconclusive. This summary determines what materials need to be collected and how the experiment’s procedure needs to be designed. It should also include variables and constants. A variable is something you change. It can be a factor, trait, or condition that can exist in differing amounts or types. There are independent and dependent variables. An independent variable is the variable changed by the scientist. For example, in an experiment testing how the number of setae on a gecko’s feet affects the gecko’s adhesiveness, the independent variable would be the different number of setae on the model gecko feet. To ensure a fair trial, a good experiment has only one independent variable. The scientist changes the independent variable to observe what happens. The dependent variable is what happens as a result of the independent variable. For example, the adhesiveness of the model feet is the dependent variable. A constant is a quantity that remains the same in an experiment. Constants allow scientists to isolate one variable at a time to ensure the experiment results are valid. 5. Once a scientist has decided on an experiment, they vertically list the materials with quantities and the step-by-step procedure. Information related to safety is also included. Carefully documenting this information is important because scientific results are not valid unless someone can replicate the exact experiment. 6. To help other readers understand the experiment set-up, a scientist makes a scientific diagram of the experiment-in-progress. The diagram is the size of a person’s hand, is drawn in pen, includes a title, and labels all of the materials used.


7. Scientists then conduct their experiment. The results of the experiment are data—the measurements and observations gathered from an experiment. Data are typically organized in a table (e.g., a table of height, time, or volume measurements). Graphs can help scientists make sense of data and allow data to be communicated visually among colleagues. For example, scientists look for patterns in data that suggest a cause-and-effect relationship, where one event or thing is the result of the other. A pattern is something that happens in a regular and repeated way. 8. The final step is to use the data to develop a conclusion—a summary of what a scientist has learned about the hypothesis, using data from the experiment as evidence. The conclusion is written out in full sentences and uses the data to argue whether the original hypothesis was true, false, or inconclusive. If results are inconclusive, meaning they do not confirm or deny the hypothesis, the scientist needs to design a different test. Most scientific experiments lead to theories

that require more testing. Experiments can also lead to scientific knowledge that engineers can then apply to create technologies that solve problems. For example, laboratories around the world have applied what is known about setae and gecko adhesiveness to design materials and other technologies, including synthetic setae on robots.

© Biomimetics and Dexterous Manipulation Laboratory, Stanford University

Engineers use scientific knowledge to design new technologies, such as

this robot with synthetic setae.


When designing new materials, materials scientists look for connections between the underlying structure of a material, its properties, how it can be changed, and what it can do. There are currently more than 300,000 different known materials, and as scientists create and combine materials in new ways, that number continues to increase. A material’s structure is directly related to its function. Structure is the way in which parts are put together to form a whole, while function is the normal action of something, or how something works. Understanding a material’s structure begins with a basic understanding of matter—anything that has mass and takes up space. Mass is a physical property of matter. It is a measure of the amount of matter that makes up an object or substance, and it is measured in grams (g).

To understand why a material has the properties it does, scientists begin with the atoms that make it up. An atom is the smallest piece of matter that has the properties of an element—substances that are made up entirely of one kind of atom. Many properties that a material has are a result of the atoms that make it up.

Atoms are so small that we

cannot see them without special instruments. Because of this, scientists use scale to understand how atoms relate to everyday objects. Scale is the size, extent, or importance (magnitude) of something relative to something else. For example, think about all of the atoms that make up a grapefruit. If each atom were the size of a blueberry, the grapefruit would be the size of Earth.

Structure and Function of Materials

The properties of aluminum, and its resulting functions, are caused by its atomic structure.


Atoms themselves are made up of smaller particles, called protons, neutrons, and electrons. The protons and neutrons group together in the nucleus. These smaller particles are much smaller than the atom itself. If you were to open up the blueberry (representing the atom), the nucleus would be too small to see. If you were to make the blueberry the size of a football field, you would just be able to see the nucleus. It would be the size of a small marble. The nucleus is very dense because it holds all of the atom’s protons and neutrons. Most of the atom’s mass—99.9 percent—comes from the protons and neutrons. Protons have a positive charge (+) and attract negatively charged electrons (-). Protons also pair with neutrons (0). Electrons have a negative charge (-) and are attracted to positively charged protons (+). The electrons are in constant motion around the nucleus. However, most of the atom is filled with empty space. There are vast regions of space between each of the electrons and between the electrons and the nucleus. Scientists use what they know about an atom’s structure to create a scale model of an atom. Scale models are useful for scientists who want to understand how the various parts of the atom interact. This is because an atom is a system—a set of connected, interacting parts that form a more complex whole.

Atomic Structure

An atom is a system, made up of smaller, interacting parts.


Scientists don’t often work with individual atoms because they are too small to see without special instruments. Instead they work with elements, such as a gold bar or helium gas. An element is a pure substance, which means it is made entirely of one kind of atom that has distinct properties that do not vary

from sample to sample. For example, in the picture to the left, each gold bar is made up of many billions of gold atoms. It is the structure of the gold atom that gives the gold bars the properties that they have. Many of an element’s properties are determined by the number of protons and neutrons its atoms have. Other properties are determined by an atom’s number and arrangement of electrons.

Most materials scientists agree that the single most important event that happened in their field came in 1864, when Russian scientist

Dmitri Mendeleev put together a chart called the Periodic Table of Elements. This chart arranged all of the known elements according to their properties. When Mendeleev developed the periodic table, there were 63 known elements. His real genius was in predicting that elements existed that hadn’t yet been discovered. His prediction was correct. There are currently 118 known elements, with the last four officially added just in 2015. These 118 elements are the only substances needed to make all of the materials that exist. In the human body, there are billions of atoms, but scientists believe that more than 95 percent of the body is made up of just six elements: hydrogen, carbon, nitrogen, oxygen, phosphorous, and calcium. The first 94 elements are believed to occur naturally. The rest are synthetic. Most of the elements that have been created last only seconds, at most, before breaking apart into smaller elements. Most new elements are made by scientists smashing together different existing elements in an instrument called a particle accelerator. Scientists are continuing to search for new elements.

Working with Elements

Gold is an element, made up of billions of gold atoms.


iron

silicon

Each element on the periodic table is assigned a symbol and a number. The symbol comes from the name of the element’s atom (in English or Latin), and the atomic number comes from the number of protons found in the atom’s nucleus. Neutrons and electrons don’t define an element because the number of neutrons and electrons in an atom can fluctuate. The periodic table is organized from top to bottom in groups by increasing atomic number, revealing some patterns among the elements. For example, an element’s place on the periodic table indicates some of its properties, including how reactive its atoms are and whether it is a metal, nonmetal, or metalloid. Metals are shiny, malleable, and good conductors of electricity and heat. Almost 75 percent of all elements are metals, including mercury, zinc, gold, copper, iron, and other elements in columns 1-12 of the periodic table. Nonmetals are brittle, dull, and poor conductors of electricity and heat. There are only 17 nonmetals on the periodic table. Gases and elements on the far right of the periodic table are nonmetals. Carbon, hydrogen, and oxygen are examples of nonmetals. Metalloids are found between metals and nonmetals on the periodic table. They are also called semiconductors because depending on what other molecules are around, they can sometimes conduct electricity. Metalloids have properties of both metals and nonmetals, such as being shiny and hard, but brittle. Boron, silicon, and arsenic are metalloids.

coal, which is primarily carbon

Periodic Table of Elements

The periodic table provides information about each element.


In order to understand how materials scientists can create new materials with specific properties designed for a particular purpose, scientists need to understand the relationship between matter and energy because matter can only change when enough energy is present. Energy is the ability to do work. Work is any change in position, speed, or state of matter due to force (a push or pull that acts on an object, changing its speed, direction, or shape). Examples of work including heating an object or moving an object. Energy can be stored or in motion. Potential energy is energy that is stored. Kinetic energy is the energy of motion. Energy of one kind can transform (change) into energy of another form in an energy system. For example, all matter has a form of energy called thermal energy, which is the motion of atoms and molecules in a substance or object as its temperature increases. The faster that atoms and molecules move, the more thermal energy they have and the warmer they become. The amount of thermal energy present in a substance

determines whether that substance is a solid, liquid, or gas because thermal energy changes the motion of molecules. However, it doesn’t change the chemical structure of the substance. For this reason, a change of state is considered a physical change. Whether you freeze or boil a cup of water, the water molecules are still water molecules.

Thermal energy determines a substance’s state.

Energy Changes Matter

Boiling water is a physical change because the structure of the water

molecules doesn’t change.


All matter also has a form of potential energy that is stored in the bonds holding together atoms and molecules. This is called chemical energy, and it is what allows new molecules to form. A molecule is made up of two or more atoms bonded together. To bond means to join together. Understanding the structure of atoms and how they combine to form molecules is an important part of materials science because each kind of material has the properties it does because of the number and kind of atoms that make it up. For example, oxygen is made up of oxygen atoms bonded together, so it is a molecule. Water (H2O) is a molecule made up of two hydrogen atoms and one oxygen atom bonded together. Water, like gold, is also an example of a pure substance because it is made up entirely of one kind of atom or molecule that has distinct properties that do not vary from sample to sample.

With only three atoms, water is a small molecule. Other molecules can be much larger. One molecule of vitamin C (C6H8O6) is made up of 20 atoms: 6 carbon atoms, 8 hydrogen atoms, and 6 oxygen atoms. Some molecules are made up of many thousands of atoms bonded together.

Forming Molecules

Oxygen, hydrogen, and water are all molecules.


Molecules are formed as a result of a chemical reaction between two or more atoms. In a chemical reaction, the atoms that make up the original substances are rearranged into new substances that have different properties from the original substances. For example, at normal room temperature, the elements oxygen and hydrogen are both gases. When hydrogen and oxygen bond in a molecule of water, they change into a liquid instead of a gas at room temperature. These changes are chemical changes because they rearrange the chemical structure of the substances through a chemical reaction. In any chemical reaction, the atoms and molecules that interact together are called reactants. The atoms and molecules produced by the reaction are called products. Together, the reactants and products form a system. The environment is everything else, including the air or any substance mixed with the reactants. It’s important to note here that reactants are sometimes dissolved in other substances, such as water. The dissolving substance (such as the water) is called the solvent. When this occurs, the solvent in which the reactants are dissolved is part of the environment. The total number of atoms does not change in a chemical reaction. Because of this, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction. This is called conservation of mass, which is the theory that states that matter is never created or destroyed. This means that the more reactants you add to the chemical reaction, the more products will form.

Chemical Reactions


It is always true that mass is conserved in a chemical reaction. However, this can be difficult to measure in the real word because matter can interact with the environment. For example, if a gas is produced, it will fill whatever space it is in, which is impossible to measure. For this reason, scientists sometimes conduct closed-system experiments, in which matter cannot be exchanged with the environment, when they want to isolate the reaction from the environment. The system of a chemical reaction interacts with the surrounding environment. As the reactants combine and rearrange, energy is exchanged between the system and the environment. Every chemical reaction needs energy to get started. This initial input of energy is called activation energy. For example, when someone strikes a match to light a candle, they provide the activation energy needed to start a fire, which is a chemical reaction. Once the reaction begins, some reactions absorb more energy from the environment than they release. Others release more energy into the environment than they absorb.

Energy in Chemical Reactions

When you strike a match, you provide the activation energy.


Whenever a process occurs in which the system absorbs heat, it is called endothermic. “Endo-” means to draw in. In an endothermic reaction, the environment’s temperature decreases. This is because the reaction has absorbed energy from the environment. Endothermic reactions occur because the reactants have less energy than the products. Because energy is never created or destroyed, the energy needed by the products is transferred from the environment and absorbed into the system.

We can’t observe these changes at the molecular level, but we can measure the temperature change that results. We see evidence of this transfer of energy when the environment’s temperature decreases because it means that the reaction has absorbed energy from the environment.

Endothermic Reactions

Citric acid and baking soda combine in an endothermic chemical reaction.

Endothermic Reaction


Any process in which the system loses heat to the environment is called exothermic. “Exo-” means to give off. Because the energy is released as heat, the environment’s temperature will increase. In an exothermic reaction, the reactants have more energy than the products. Because energy is never created or destroyed, the extra energy released by the reactants is transferred into the environment.

There are many examples of exothermic reactions. For example, whenever you light a match, you are witnessing an exothermic reaction take place. The light and heat produced are evidence that energy is being released into the environment. Another common example of exothermic reactions occurs in certain animals that produce and release light. Called bioluminescence, this phenomenon occurs in animals that live in the ocean, as well as some land animals such as fireflies.

The strength of a chemical reaction can be measured by the amount of energy absorbed or released by the reaction. When more reactants are added, it increases the amount of energy that is absorbed or released.

Exothermic Reactions

The light produced by this firefly is a result of an

exothermic chemical reaction.

© art farmer CC

Exothermic Reaction


Some chemical reactions produce large molecules called polymers, which are made up of many smaller molecules bonded together in a repeating chainlike pattern. Polymers are all around us. DNA, spider silk, natural rubber, and protein are all examples of naturally occurring polymers. Plastics, nylon, acrylic, and Teflon are examples of synthetic polymers.

Teflon, the material used to make the non-stick coating of cooking pans, is a polymer that is made from molecules of carbon and fluorine atoms. Many polymers are made from compounds of carbon and hydrogen. The carbon atoms are covalently bonded together to form the backbone of the molecule, while the hydrogen attaches to each carbon atom. It is the structure of the fluorocarbon molecule that gives Teflon many of its desirable properties. The fluorine atoms surround the carbon atoms, repelling outside atoms that try to react with the carbon. Because of this, Teflon is highly unreactive. It is also believed to be the only known surface that

geckos cannot stick to.

Teflon was first discovered by accident in 1938, by a young scientist named Roy Plunkett. At the age of 27, Plunkett was working in the lab, trying to come up with a chemical to use in refrigerators. He decided to use a gas, which he stored in metal cans with a valve release (similar to hair spray cans today). On the morning he tried to release the gas from the can, he realized he couldn’t get the gas out of the can. However, the can weighed the same as it had when the gas was added. Plunkett was curious as to what was going on. He cut open the metal can, and discovered that the gas had turned into a white powder that was unusually slippery. Plunkett was intrigued. He tested the unknown white powder for its properties. Plunkett discovered that the white powder was heat resistant and had a low surface friction, which meant that most other substances wouldn’t stick to it. That white powder would later be named Teflon. Without meaning to, Plunkett had produced a synthetic polymer.

Polymers

The structure of Teflon gives it its properties.


All polymers, including silk, Teflon, and nylon, share certain properties because they are all huge molecules, with hundreds and sometimes thousands of atoms per molecule. Their structure gives them unique properties. For example, polymers are so large that they become entangled with each other. Think of one polymer molecule as a piece of cooked spaghetti. In a bowl of spaghetti, that one piece of cooked spaghetti gets tangled up with all of the other pieces of pasta. It is very difficult to separate one piece of spaghetti from the remaining pieces because the strands of spaghetti are tangled together. Polymer molecules are arranged in a similar way. Because of this structure, polymers tend to be strong and resistant to breaking. In contrast, small molecules like water do not tend to get tangled with each other because each water molecule is separate from the other. Polymers also tend to be both light and strong, and also resistant to chemicals (which is why Teflon is a non-stick coating on cooking pans). Another way of thinking about the structure of polymers is to picture a box filled with steel chains. Each chain is made up of hundreds of individual links, but the chains themselves are not connected to any other chain. In this example, each steel chain represents one polymer molecule, made up of hundreds or thousands of atoms (individual links). If you were to reach into the box and grab a chain, you could pull out an individual chain. But now imagine that you add a lot of tiny magnets into the box. Those magnets would attract the steel chains, connecting the individual chains into one large mass of chains. If you were to reach into the box and grab a chain now, you would pull out the entire mass of chains.

Structure and Properties of Polymers

Polymers are like steel chains. © okanakdeniz


To understand how this applies to polymers, let’s look a simple chemical reaction between school glue and a substance called sodium borate, which is common in detergents and cosmetics. By itself, glue is a synthetic polymer made up of molecules of polyvinyl acetate. It is a sticky liquid. Sodium borate is a solid powder that can be dissolved in water. Remember that box of steel chains. The glue is like the steel chains, made up of long chains of molecules strung together. When you dissolve sodium borax in water and then add it to the glue, it has the same effect as adding the magnets to the steel chains. The sodium borate molecules react with the molecules of polyvinyl acetate, bonding at random places on the polyvinyl acetate molecule chains. The result is a new substance that is made up of tangled, long, flexible, cross-linked chains that are stretchy and bouncy. The unique properties of the new polymer can be changed by using different amounts of any of the reactants.

Making Bouncy Ball Polymers

Polyvinyl acetate and sodium borate combine to form a polymer.


Understanding the relationship between a polymer’s molecular structure and its properties allows materials scientists to design new synthetic materials. For example, in 1930, several years before the surprise discovery of Teflon, a researcher named Wallace Carothers was using his knowledge of polymers to create new synthetic materials that could be used in clothing. He wanted a material that was durable, flexible, and elastic. He had a good understanding of basic polymer structure: namely that they were large molecules made up of long chains of repeating units of atoms, which gave them the properties he was interested in. He had been experimenting with synthetic polymers for six years. He and his team of researchers began by creating the first “polyester” fibers that became extremely elastic when cooled. However, this material wasn’t very practical because it had a low melting point. This meant that laundering and ironing weren’t possible. So Carothers and his team kept experimenting with different chemicals in an effort to come up with a polymer that was flexible and sturdy, but also had a high melting point. Six years later, they combined two chemicals: hexamethylene diamine and adipic acid. When combined, a chemical reaction occurred that produces gooey blob that can be drawn into long, thin, elastic fibers. Each molecule consists of 100 or more repeating units of carbon, hydrogen, and oxygen atoms, strung in a chain. This was the first nylon. One of the reasons that nylon is so resilient is that a single strand may be made up of more than one million molecules. When stretched, each of those molecules takes some of the pressure.

Nylon’s molecular structure (above) gives it its properties (below).

Discovering Nylon


The first product that nylon was used in was a nylon toothbrush. It then quickly became famous for its use as women’s stockings. Today it is used in various clothing, as well as carpets, hoses, parachutes, racket strings, and dental floss. The difference between a pair of nylon stockings and dental floss is how the nylon is manufactured. Manufacturing is an operation that transforms raw materials—the basic materials from which a product is made—into a finished product. Manufacturing is what builds all of the “stuff” that surrounds you, from the nails and screws that hold your desk together to your cell phone, your clothes, and your car. Manufacturing processing refers to the series of operations that result in this transformation from raw materials to a finished product. Different industries follow different processes, depending on the product being made. However, all manufacturing processes involve several basic steps. First, the manufacturing process has to form the materials into the desired shape. Secondly, it has to alter or improve the material’s properties to better achieve the desired function. Polymers are useful in manufacturing because they can be processed in many different ways. This is the main reason we see examples of polymers all around us. For example, extruding is a common physical process when manufacturing many materials, including polymers. To extrude means to shape a substance by forcing it through a tool called a die, which cuts or shapes materials. Polymers can be shaped by extrusion into thin fibers, heavy pipes, or food containers. Cutting and sanding are other examples of physical processes that shape materials without changing their chemical structure. Polymers can also be processed in a way that changes their chemical structure. For example, some kinds of plastic are heated to make them more rigid. Nylon is cooled to make it more elastic.

Turning Raw Materials into Products


Crayons are a simple product that are manufactured from the raw material of paraffin wax. Paraffin wax is a material that is made up of between 20 and 40 atoms of carbon, as well as hydrogen atoms. It is a white, odorless, tasteless, waxy, pliable solid. That paraffin wax is the main ingredient of crayons. Because of this, twice a week, trains with cars full of paraffin wax pull up to the Crayola factory in Pennsylvania.

When the trains reach Crayola’s factory in Pennsylvania, the wax is heated until it melts. Here, it’s important to know about more of paraffin wax’s properties, including its melting point. Crayons melt at 40 degrees Celsius (104 degrees Fahrenheit).

Then, the wax is mixed together with color pigments, which are like colored flour. For this step again, scientists need to know the properties of paraffin wax and how it interacts with other materials. Paraffin wax doesn’t mix with liquids, so the color pigments need to be in solid (powder) form. Crayola makes 120 different colors of crayon. The wax is also mixed with other chemicals, which the company doesn’t reveal. These ingredients give crayons the specific properties that they have. Once the color pigments are mixed with the wax and stirred so that the color is evenly distributed throughout, the hot wax mixture is poured into molding machines. A mold is a hollow container that is filled with a liquid or a pliable material such as the heated wax or plastic. A single Crayola mold makes 1,200 crayons at a time. Cold water travels through tubes in the molds to cool the wax down. When the material cools, it hardens in the shape of the mold. This manufacturing process is often called forming, during which the shape of the material is changed into a specified form.

Making Crayons

different Crayola colors


In about four to seven minutes, the wax in the mold cools and becomes solid. Workers scrape off the top of the mold, and the extra wax will be melted and used again. The mold then extrudes the crayons. After they have been extruded, each crayon is inspected for breaks and chips, as well for bubbles, which can appear if mixing has not been complete. Those crayons that are rejected will be re-melted and molded. This process is called quality control, a process that reviews the fitness of production by comparing items produced to a production standard. This process includes product inspection, where someone examines the final product for unacceptable defects, such as cracks. Then a machine puts labels on the crayons. Before 1943, farmers used to hand-wrap the crayons during the winter months. However, using a machine allows many more crayons to be labeled in a much shorter time period.

People take crayons to a collating machine where 16 different colors of crayons are put together and mixed into a little box. More colors in more little boxes are added together in the final product. This process is called assembling, when all of the components are assembled into a whole product. Efficiency is an important factor at this point in the process. The fewer parts needed to assemble the product, the less time—and therefore lower costs—it will take to put it together. Additionally, manufacturers try to design parts that are easy to hold, move, and attach to decrease the amount of time needed to put all of the parts together.

Crayola’s manufacturing process is very efficient. It allows the company to manufacture 8,500 crayons per minute, 13.5 million crayons per day, and 3 billion crayons per year. It is so efficient because

many of the processes are done by machines.

Part of the manufacturing process is assembling the

crayons in the box.

Assembling Crayons


Factories around the world manufacture many products that our society depends on, from crayons to medicine, cars, clothes, computers, phones, and construction equipment, to list just a few. In each of these factories, manufacturing processes are carefully followed. Manufacturers need to follow set processes because they want to make sure that the goods they produce meet certain design and safety standards. The process helps ensure that every step is properly followed and that the end products are equal in design, durability, and safety. Manufacturing processes depend on the materials used and the type of product being manufactured. For example, a company that makes a variety of different toys has a manufacturing process that has 65 major steps. Boeing is another company for whom a solid manufacturing process is essential. It has the largest building in the world,

located in Everett, Washington. From this location, it has manufactured almost 4,000 airplanes. In 2006, Boeing employees realized that they could improve the efficiency of their manufacturing process of their 777 airplane. In the traditional process, the airplanes

being made remained stationary, parked wing to wing next to each other. However, employees

realized they could improve their process by switching to a moving assembly line, where the planes were positioned nose to tail so they could move. Having a process in place was important because the 777 airplane has about 3 million parts. When complete, it weighs 166,441 kilograms (366,940 pounds). Just the paint alone adds hundreds of pounds of weight to the plane. Painting is part of finishing, the process when additional features are added to complete the look of the product. Painting and polishing are part of the finishing process, as is adding decorative features to the product.

a finished Boeing 777

Improving Efficiency


Review the official MSDS inserts for borax and potassium iodide in the appendix in the back of your binder. Proper handling and safety must be followed at all times. The information below serves as general guidelines for using these chemicals in the classroom. Always refer to the official MSDS sheets for comprehensive information.

Borax

General Guidelines: Borax, also known as sodium borate, sodium tetraborate, or disodium tetraborate, is a boric acid disodium salt. Powdered borax is white, consisting of soft, colorless crystals that dissolve easily in water. Borax is used in detergents, cosmetics, enamel glazes, and many other materials. Physical Safety:

• slightly hazardous in case of skin contact (irritant), eye contact (irritant), ingestion, or inhalation

Storage: • Keep the container tightly closed in a cool, well-ventilated area.

Handling in the lab: Students must wear properly fitting goggles and disposable gloves during the entire experiment. Read and follow all safety warnings on MSDS sheet.

• In case of ingestion, call a physician or Poison Control Center.

Disposal: Any remaining diluted borax solution can be disposed of via sewer/drain.

Potassium Iodide

General Guidelines: Potassium iodide is referred to by the chemical formula KI and is an inorganic compound. It was used as a component in film photography before the discovery of silver iodide; it is also used in solar cells. Physical Safety:

• Slightly hazardous in case of skin contact (irritant), eye contact (irritant), ingestion, or inhalation. Safety goggles and disposable gloves must be worn at all times. See MSDS sheets for heath ratings and other chemical safety information.

Storage: • Keep the container tightly closed in a cool, well-ventilated area. See MSDS sheet for

additional guidelines. Handling in the lab: Students must wear properly fitting goggles and disposable gloves during the entire investigation. Read and follow all safety warnings on MSDS sheet.

• In case of ingestion, call a physician or Poison Control Center. See MSDS sheet for other first-aid information.

Disposal: See MSDS sheet for disposal recommendations.

Materials Safety Overview


Objective: In this intro lesson, students are introduced to the scientific process and set up their laboratory notebooks.

Materials: Consumable A. Laboratory notebooks – 1 per student Non-Consumable B. STEM Cycle Visual – (not shown) C. Scientific Process Visual – (not shown) D. Who is a Scientist poster – (not shown) Teacher Preparation:

• This brief lesson is intended to take one class to complete. • Download the visuals from the KnowAtom Interactive website. • Find a location in the class to display the “Who is a Scientist?”

poster. • Prepare to watch the video(s) about Eva Vertes with your class

at the beginning of the Socratic dialogue and the video about materials science at the end of the dialogue. The videos can be accessed directly from the KnowAtom Interactive website.

Student Reading Preparation:

• Students read the Intro Section of the student lab manual. At the beginning of the school year, the lab manual can be read aloud in class. This will help to model for students how to read closely for understanding. For example: o Pause at key points during the reading to emphasize

connections between examples in the reading and broader

Intro Lesson: Using a Scientific Process

A


concepts. For example, ask why a certain example was used to support the reading’s main point.

o Use “why” and “how” questions to connect ideas in the reading to student experiences. Over time, the goal is for students to come up with these questions on their own.

• Remember that the purpose of the reading is to provide students with enough background scientific knowledge so that they can generate their own questions, which they will further explore in the Socratic dialogue and hands-on portion of the lesson.

Socratic Dialogue:

• The Socratic dialogue serves as the bridge between the nonfiction reading and the lab portion of the lesson.

• Remember that a Socratic dialogue cannot be scripted. The following framework is intended to help teachers visualize the lesson’s flow of ideas and as support as they navigate through the big ideas in this lesson. The bracketed italicized text is provided for teacher reflection as students formulate and work with their own ideas and the ideas of their peers.

• Students should be discussing what they think and why they think it. The role of teacher is to help make sure rules of fair discussion are being followed; if things get too far off, they can be an interested skeptic who helps pivot the dialogue. Not sure how to set up a Socratic dialogue? Check out www.knowatom.com/socratic for an in-depth look at how to hold a next generation Socratic dialogue in the classroom.


Block 1-1: How Scientists Answer Questions 1. Watch one or more of the videos of Eva Vertes, a cancer researcher whose love of science began as a 9-year-old on a camping trip. There are 3 videos totaling 6 minutes, which can be accessed with the video link on the KnowAtom Interactive website. After watching the video, students have a Socratic dialogue about what they observed. 2. Socratic dialogue should begin with a student question. The following sequence is one potential progression of big ideas. However, these big ideas are part of a dynamic, three-dimensional context so students may progress through them in different ways. While the big ideas are an important part of the discussion, teachers shouldn’t expect the dialogue to follow the same linear progression as this example sequence. � Big Idea 1: Science is new knowledge gained from

experiments. It is the search for explanations about the natural world, and scientists use evidence to form conclusions that support those explanations. Possible back-up seed questions that teachers could consider are: o In the 1st video (Monkeys with Ebola), what first got Eva

excited about science? [She was fascinated by all of the gruesome effects of Ebola.]

o In the same video, what was the main question that Eva was trying to answer when she started working at the Alzheimer’s clinic? [She was trying to answer the question of what might be able to inhibit or reduce the brain cell death that occurs in Alzheimer’s patients.]

o In the 2nd video (Secret: Runner), why does Eva compare running and research? [She says both require an inner drive. In running, it’s can you do it faster? In research, it’s whether there’s a different way to do something, to ask


further questions that come about as a result of the first investigation.]

o Why do scientists ask questions? [Scientists ask questions that they investigate, gathering data that will help them answer their questions in an evidence-based conclusion.]

o Can anyone think of a time when they were scientists? What question were they trying to answer, and how did they go about finding an answer to the question? [Anytime someone asks a question and then gathers evidence to find an answer to that question, they are being a scientist.]

3. Consider displaying STEM Cycle Visual as a backdrop to Big Idea 2. � Big Idea 2: Science and

engineering are both part of the STEM cycle. STEM stands for science, technology, engineering, and math. They are connected and interact with one another, but they are also different. Possible back-up seed questions that teachers could consider are: o Why are science and engineering connected in the STEM

cycle? [Scientists gain new knowledge as a result of their experiments. Engineers apply that scientific knowledge to create new technologies that solve problems.]

o How are science and engineering different? [Engineers apply scientific knowledge to create new technologies that solve problems. Scientists gain new knowledge as a result of their experiments. Math is a tool that both scientists and engineers use to capture results and communicate those results to others.]


o How does the field of materials science show the STEM cycle in action? [Materials scientists are scientists because they ask questions about the structure and properties of different materials. However, they also use that scientific knowledge to design new materials that fulfill certain functions.]

4. Watch the 4-minute video “What is materials science?” The video can be accessed with the video link on the KnowAtom Interactive website. Throughout the unit, students will explore various aspects of materials science, investigating how the structure of materials is directly connected to their function, and how scientists use scientific knowledge to design new materials that solve problems. After watching the video, students have a Socratic dialogue about what they observed. Students ask questions about their observations. Possible back-up seed questions that teachers could consider are:

� How does the field of materials science affect our lives? � Why do materials scientists care about the structure and

properties of matter? � What problems are materials scientists still trying to address?

Transition to student lab notebook set-up:

NOTE: This lesson is the only lesson in which students should be directed step by step because they are setting up their lab notebooks. In all future labs, students should use the scientific process to guide them as they work independently with their teams to move from a question to a data-based conclusion, recording the process in their lab notebooks.


1. Each student collects 1 laboratory notebook. Students write their name, class, grade, and subject on the cover and on the first page of their notebooks. Students should also number each right-hand page up to 10. Page numbers are written in the top right corner, and writing is only done on right-hand pages. 2. Students title page 2: “The Scientific Process.” Consider displaying the Scientific Process Visual, which is also found in student lab manuals on page 10, to have a dialogue about the scientific process. � Big Idea 3: The scientific process

provides scientists with a logical framework to work from a question to a data-based conclusion. Possible back-up seed questions that teachers could consider are: o Why is it important to follow a process in both science

and engineering? [Because a process is a series of steps designed to meet a goal, it gives scientists and engineers a clear framework to follow to achieve their goals. It’s like stepping stones that move them from the question or problem to an evidence-based conclusion.]

o What would happen if scientists tried to conduct an experiment without first asking a question? [Without a question, scientists wouldn’t know how to set up the experiment because they wouldn’t be able to form a hypothesis.]

o Why are data important in an experiment? [Data are the measurements and observations gathered from an experiment. Data will be used as evidence in the conclusion to determine whether a hypothesis is true, false, or inconclusive. Quantitative results are evidence that reveal information about the hypothesis. This evidence is


necessary to support a claim in a conclusion, which is more reliable than forming a conclusion based on opinion or subjective observation.]

3. Students list each step of the scientific process, along with brief descriptions, in their lab notebooks. 4. Students title page 3: “The Engineering Process.” Students will record the steps of the engineering process on this page in Unit 2. 5. Students title page 4: “Table of Contents.” When students fill this in, each entry will include the lab number, title, date, and first page number (example shown below). Leave pages 5-9 blank for the Table of Contents.

6. For each new lab entry, students write (under the page number) the title of the experiment, date, and partner's name (if applicable). Explain that the lab title, date, and page number of each lab are also entered in the table of contents chronologically. Remind students that lab notebooks should be neat, written in pen, and that all errors must be crossed out, never erased or scribbled. See pages 79-81 for a sample lab notebook entry.


Objective: Students analyze the observable properties and thermal data produced by the combination of two substances to determine if a chemical reaction occurred.

Materials: Consumable A. Goggles – 1 per student B. “Chemical Reactions Investigation” sheet – 1 per student (lab manual) C. Disposable gloves – 1 pair per student D. Plastic spoons – 2 per team E. Foam cups – 2 per team F. 30-mL graduated cups – 4 per team G. Baking soda – 3 grams per team H. Hydrogen peroxide – 30 mL per team I. Vinegar – 30 mL per team J. Potassium iodide (powder) – 5 grams per team Non-Consumable K. Digital scales – 1 per team L. Digital thermometers – 1 per team M. Structure and Properties of Matter Visual – (not shown) N. Atoms and Molecules Visual – (not shown)

Lesson 1: Chemical Reactions

A B

C

K

D

H

E

G

J I

L

F


Teacher Preparation:

• Download the visuals from the KnowAtom Interactive website. • Arrange several pick-up stations for teams to pick up materials

to use at their desks during the investigation. For example: o Pick-Up Station 1: goggles, disposable gloves, and student

lab manuals o Pick-Up Station 2: digital scales, plastic spoons, and 30-mL

plastic cups o Pick-Up Station 3: foam cups and digital thermometers o Pick-Up Station 4: baking soda and vinegar o Pick-Up Station 5: hydrogen peroxide and potassium iodide


• Students read the Section 1 of the student lab manual. At the beginning of the school year the lab manual can be read aloud in class. This will help to model for students how to read closely for understanding. For example: o Pause at different key points during the reading to

emphasize connections between examples in the reading and broader concepts. For example, ask why a certain example was used to support the reading’s main point.




Socratic Dialogue:

Block 1-2: Structure and Properties of Matter 1. Students watch the 5-minute video “How Concrete is Made” to begin the Socratic dialogue.

� The video can be accessed with the video link on the KnowAtom Interactive website.

2. After watching the video, students have a Socratic dialogue about what they observed and how the creation of concrete might connect to the concepts of chemical reactions. Socratic dialogue should begin with a student question. The following sequence is one potential progression of big ideas. However, these big ideas are part of a dynamic, three-dimensional context so students may progress through them in different ways. While the big ideas are an important part of the discussion, teachers shouldn’t expect the dialogue to follow the same linear progression as this example sequence. 3. Students ask questions about their observations from the video and discuss their explanations for why they think the phenomenon occurs.

� Big Idea 4: Synthetic materials come from natural resources and impact society. Possible back-up seed questions that teachers could consider are:


o What societal need does concrete fill? o What natural resources are used to create concrete? o Why does concrete have different properties from the

natural resources it comes from? 4. Consider displaying Structure and Properties of Matter Visual as a backdrop to Big Idea 5.

� Big Idea 5: To understand why a material has the properties it does, scientists begin with the atoms that make it up. Possible back-up seed questions that teachers could consider are: o How are the properties of the gecko-like material

described in the Intro Section of the reading related to its function? [The gecko-like material is adhesive, which allows it to attach and detach from surfaces easily.]

o Why do materials scientists care about the atoms that make up materials? [Atoms are the smallest pieces of matter that have the properties of an element—substances that are made up entirely of one kind of atom. Many of an element’s properties are determined by the number of protons and neutrons its atoms have. Other properties are determined by the number and arrangement of electrons in an atom.]

o How are the properties of aluminum foil related to the structure of an aluminum atom? [It is the structure of the aluminum atom that gives the aluminum foil the properties that it has (shiny, malleable, metallic, etc.).]

o How can there be just 118 elements, and hundreds of thousands of different materials? [The 118 elements join


in a variety of ways to form all of the different kinds of matter around us.]

5. Consider displaying Atoms and Molecules as a backdrop to Big Idea 6.

� Big Idea 6: Atoms combine with other atoms in a variety of combinations to form all of the matter around us. Atoms combine with other atoms to form molecules (combinations of two or more atoms bonded together). The structure of a molecule is directly related to its properties. Possible back-up seed questions that teachers could consider are: o How does a water molecule provide evidence that

molecules have different properties from the atoms that make them up? [At normal room temperature, both oxygen and hydrogen elements are gases. When hydrogen and oxygen bond in a molecule of water, they change into a liquid instead of a gas at room temperature.]

o How is the motion of atoms and molecules in a liquid different from the motion of atoms and molecules in a gas? [Thermal energy is the motion of atoms and molecules in a substance or object as its temperature increases. The faster the atoms and molecules are moving, the more thermal energy they have. The atoms in a liquid are in constant contact with one another, but they have enough energy to slide past one another. The molecules in a gas have so much energy that they move far apart and bounce around randomly.]

o Why is chemical energy a form of potential energy? [Chemical energy is energy stored in the bonds holding


together atoms and molecules. Potential energy is any energy that is stored.]

o How would you describe the relationship between energy and matter? [Matter can only change when enough energy is present. For example, all matter has thermal energy, and adding or removing thermal energy from a substance changes its state. Sometimes when energy is added, two or more substances will combine in a chemical reaction to produce new substances with different properties.]

6. Transition to the Investigation: Students construct initial explanations:

� Students work in teams of two to record their initial claims about why concrete has different properties from the natural resources it comes from. NOTE: A claim is a student’s response to a question about a phenomenon, which reveals insight into the student’s understanding of the phenomenon. Claims will vary in accuracy, detail, and complexity, which is OK.

� Students record their claim(s) on a blank sheet of paper. � Teams will re-evaluate and modify their claims after the

investigation.

Investigation: 1. Divide the class into teams of two. Stand by the materials stations and point out the different materials, including how the digital thermometers function (if needed).

SAFETY: Students must wear goggles and disposable gloves during this activity. Review the MSDS sheet for hydrogen peroxide and potassium iodide in the appendix in the back of your binder. Abridged chemical safety information is provided on page 40. Review all safety precautions with the class prior to starting the investigation.


� Students collect the materials they will need according to the quantity and type of materials listed on the investigation sheet.

� Students go to the stations to collect the materials they will use at their desks.

Pick-Up Station 1:

• “Chemical Reactions Investigation” – 1 per student (lab manual)

• goggles – 1 per student • disposable gloves – 1 pair per student

Pick-Up Station 2:

• digital scales – 1 per team • plastic spoons – 2 per team • 30-mL plastic cups – 4 per team

Pick-Up Station 3:

• foam cups – 2 per team • digital thermometers – 1 per team

Pick-Up Station 4: • baking soda – 3 grams per team • vinegar – 30 mL per team

Pick-Up Station 5:

• potassium iodide – 5 grams per team • hydrogen peroxide – 30 mL per team

Each team will:

� Investigate the question: How can you tell if a chemical reaction has taken place when two or more substances combine?


� Make claims: Work with your team to make claims about the different ways you could tell that a chemical reaction has taken place when two substances combine. Record your claim(s).

� Carry out Procedure 1: 1. Pour 30 mL of vinegar into the foam cup. 2. Measure the initial temperature of the vinegar. You may

need to wait several minutes until the thermometer gives a steady reading.

3. Add 3 grams of baking soda to the vinegar with a 30-mL cup. 4. Measure the final temperature of the solution and then

discard the solution and used cups. � Record data in Tables 1 and 2: (Sample data in red represent

typical outcomes.)

Table 1: Temperature Data

Combined Substances

Solution: Final

Temperature (°C)

Vinegar: Initial

Temperature (°C)

Temperature Change (°C) (final-initial)

vinegar + baking soda 16.0 22.4 -6.4

Table 2: Observations – Vinegar + Baking Soda Observable Properties of Substances Before

Mixing

Observable Properties of Substances When

Combined

Final Observable Properties of

Substances • The vinegar (liquid) is

clear. It has a strong odor.

• The baking soda is a

solid white powder.

• The vinegar and baking soda reacted when combined. The reaction fizzed, and bubbles rose up in the cup, showing that a gas formed.

• The white baking soda powder was no longer visible in the solution. The solution returned to its starting level in the cup. There were many gas bubbles in the solution.


2. Students collect their materials from the pick-up stations to carry out Procedure 1. Circulate around the classroom to help troubleshoot and to ask questions that gauge student thinking. Teams move on to Procedure 2 when they have completed Procedure 1 data collection. Each team will:

� Carry out Procedure 2: 1. Pour 30 mL of hydrogen peroxide into the foam cup. 2. Measure the initial temperature of the hydrogen peroxide.

You may need to wait several minutes until the thermometer gives a steady reading.

3. Add 5 grams of potassium iodide to the hydrogen peroxide with a 30-mL cup.

4. Measure the final temperature of the solution and then discard the solution and used cups.

� Record data in Tables 3 and 4: (Sample data in red represent typical outcomes.)

Table 3: Temperature Data

Combined Substances

Solution: Final Temperature

(°C)

Hydrogen peroxide: Initial Temperature

(°C)

Temperature Change (°C) (final-initial)

hydrogen peroxide

+ potassium iodide 31.8 21.3 10.5

NOTE: Students should use the lowest value or highest value observed, depending on the direction of the temperature change, when recording the temperature of the solutions. Teams should rinse the sensor and the cord of the thermometers with water and dry after collecting temperature data.


Table 4: Observations – Hydrogen Peroxide + Potassium Iodide Observable Properties of Substances Before

Mixing

Observable Properties of Substances When

Combined

Final Observable Properties of

Substances • The hydrogen

peroxide (liquid) is clear.

• The potassium iodide

is a solid white powder.

• The hydrogen peroxide and potassium iodide reacted when combined. The reaction fizzed and expanded slightly in the cup, showing that a gas formed. The air above the reaction felt warm. The solution in the foam cup turned yellow.

• There were gas bubbles in the solution and the solution is yellow.

3. Constructing explanations and engaging in argument from evidence: When students have completed the data collection portion of the investigation, they analyze their findings.

� Analyze the substances: 1. Look at the claims you recorded at the beginning of the

investigation. How did the data you collected in Tables 1-4 during the investigation support these claims?

2. Were any of the initial claims you made not supported by the data you collected in the investigation? If so, what might explain this?

3. When the vinegar (acetic acid diluted in water) and baking soda combine, products form. The chart below shows a simplified version of the reactants (vinegar and baking soda) and the products that form:


Reactants and Products Chart Reactants

1 acetic acid molecule C₂H₄O2

1 baking soda molecule

NaHCO₃

Products

1 water molecule

H2O

1 carbon dioxide gas molecule

CO2

1 sodium acetate molecule

NaC₂H₃O₂

Key: H (white) = hydrogen atom; C (black) = carbon atom; O (red) = oxygen atom; Na (purple) = sodium atom

How does the information in the chart help support the observations you made about the properties of the vinegar and baking soda before and after they combined?

� Develop and use a model: Use information from the chart and the Periodic Table of Elements in your lab manual (optional) to:

a) Develop a visual model that describes how mass is conserved in a chemical reaction. Use the blank space on the page to develop your model.

b) Label any relationships you notice between the different parts of your model.


Wrap-Up: 1. Students engage in argument from evidence:

• Students share and discuss their initial claims about how they could tell if a chemical reaction occurs when two substances combine and then explain how the data from the investigation did or did not support their claim(s). For example: o Some teams may have made several claims about what

happens when two substances combine in a chemical reaction, such as: gases are produced, the color of the substances changes, the temperature of the solution increases or decreases, etc.

o Some of the claims may or may not be supported by the data/observations, given the specific substances students reacted in the investigation. Teams should recognize that not all substances will combine, react, and change chemically in the same way.

• Students from other teams share their analysis and evaluate each other’s evidence and reasoning.

• Were the patterns in the data consistent with all teams in the class? If not, what may have caused some teams to have different data? [Answers will vary. Students compare their results and analyze possibilities for any differences, such as a difference in carrying out the procedure or possible human error.]

• Students share and discuss their analysis about how the information in the Reactants and Products Chart helps to support their observations about the properties of the vinegar and baking soda before and after they combined. o Students use information from the Reactants and Products

Chart to provide an evidence-based explanation that the change in properties of substances they observed is related to the rearrangement of atoms in the reactants into new products in a chemical reaction.


2. Students use their models to construct explanations: • Students share and discuss the visual models (drawings) they

created for the investigation to describe how mass is conserved in a chemical reaction.

• Students should recognize that the Reactants and Products Chart provides additional information about the rearrangement of molecules in a vinegar and baking soda chemical reaction. They should use information from the chart to explain that mass is conserved in chemical reactions because the number and types of atoms that are in the reactants equal the number and types of atoms that are in the products.

• Models may include labeled drawings that organize the different components of the chemical reaction (given in Table 3) to highlight specific relationships, including: o the types and number of molecules that make up the reactants o the types and number of molecules that make up the products o labels for the number of each type of atom in the reactants o labels for the number of each type of atom in the products o the mass of each type of atom in the reactants and the mass of

each type of atom in the products (found in the periodic table) o the total mass of the reactants compared to the mass of the

products

• Students discuss the components of their models and describe the relationships between the different components of the model. Relationships should include the following: o Each molecule in each of the reactants is made up of the same

type(s) and number of atoms (i.e. each molecule of bicarbonate has the same number and types of atoms).

o When a chemical reaction occurs, the atoms that make up the molecules of reactants rearrange and form new molecules (the products).


o The number and types of atoms that make up the products are equal to the number and types of atoms that make up the reactants.

o Each type of atom has a specific mass, which is the same for all atoms of that type. (Atomic mass for each element can be obtained on the Periodic Table of Elements.)

• As students make connections and share their models, some

students may choose to modify their original models to incorporate any changes to their understanding of how mass is conserved in a chemical reaction.

3. Connect to phenomena: Students continue the dialogue to connect the chemical reactions they observed during the investigation with the phenomenon of how concrete is formed.

• As a class, students discuss how their results and analysis from the investigation support, do not support, or add on to the ideas and claims they made at the beginning of the lesson about how concrete is formed and why it has different properties from the natural resources it comes from. Possible new connections may include: o The atoms and molecules that make up the original

substances (sand, crushed rock (aggregate), water, and cement (limestone, clay, and other elements like iron) are rearranged in chemical reactions to produce concrete.

o Energy is needed to cause these chemical reactions to occur.

• Student discussion may lead to new questions. Students can reason through these new questions, using evidence from the investigation results, lab manual, or other sources. Possible extension questions include: o How do the properties of concrete make it so useful? o Are there any downsides/negative effects to making

concrete?


Objective: Students design an experiment to test how increasing the amount of borax in a polymer bouncy ball affects its bounce height. Materials:

Consumable A. Goggles – 1 per student B. Laboratory notebooks – 1 per student C. Disposable gloves – 1 pair per student D. Plastic cups (3.5 oz) – 4 per team E. Plastic spoons – 1 per team F. Craft sticks – 2 per team G. Borax powder (sodium borate) – 15 grams maximum per team H. School glue (polyvinyl acetate) – 40 grams per team I. Warm water – 60 mL per team teacher provides – (not shown) J. Plastic bags – 1 per student K. Food coloring – 2 colors shared L. Plastic cups (30 mL graduated) – 2 per team Non-Consumable M. Digital scales – shared N. Graduated measuring containers – shared O. Measuring tape – 1 per team P. Structure of Polymers Visual – (not shown)

Lesson 2: Polymer Structure and Function

A B

C

K

E

O

G J

F

H

N

D

L

M


Teacher Tool Kit Q. Masking tape – shared Teacher Preparation:

• Download the visuals from the KnowAtom Interactive website. • To save time, prepare photocopies of the Facilitated Procedure,

Blank Data Table, and Blank Graph for each student using the copy master on pages 82 and 83.

• Arrange water collection stations by filling the graduated measuring container(s) with warm water. Put 1-2 containers at each station. Teams should go to these stations to access water during the lab.

• Arrange a borax station for teams to collect borax powder during the lab.

• Arrange 1-2 polyvinyl acetate (school glue) stations for teams to collect glue during the lab. Each station should contain several bottles of glue.

• Arrange several pick-up stations for teams to pick up materials to use at their desks during the experiment. For example: o Pick-Up Station 1: disposable gloves, goggles, and digital

scales o Pick-Up Station 2: plastic spoons, craft sticks, 30-mL

graduated cups, and plastic cups (3.5 oz) o Pick-Up Station 3: measuring tapes, masking tape, and

plastic bags


• Students read the Section 2 of the student lab manual. At the beginning of the school year the lab manual can be read aloud in class. This will help to model for students how to read closely for understanding. For example:

Q


o Pause at different key points during the reading to emphasize connections between examples in the reading and broader concepts. For example, ask why a certain example was used to support the reading’s main point.



Socratic Dialogue:

Block 2-1: Polymer Structure and Properties

1. Socratic dialogue should begin with a student question. The following sequence is one potential progression of big ideas. However, these big ideas are part of a dynamic, three-dimensional context so students may progress through them in different ways. While the big ideas are an important part of the discussion, teachers shouldn’t expect the dialogue to follow the same linear progression as this example sequence. 2. Consider displaying Structure of Polymers Visual as a backdrop to Big Idea 7.

� Big Idea 7: Some chemical reactions produce polymers—large molecules that are made up of many


smaller molecules bonded together in a repeating chainlike pattern. This structure affects the properties of the substance. Possible back-up seed questions that teachers could consider are: o Why is Teflon a synthetic material? [It is made by humans,

but it is made up of naturally occurring substances—the elements carbon and fluorine.]

o Why is Teflon useful? [It is heat resistant and has a low surface friction, which means that most other substances won’t stick to it.]

o Given those properties, why is Teflon commonly found in items such as pots and pans? [Teflon is a non-stick material that coats pots and pans so that food doesn’t stick to the pan.]

o How does the structure of polymers relate to their properties? [Polymers are so large that they become entangled with each other. The polymer molecules can slide past one another, but they are still connected together. Polymers tend to be strong and resistant to breaking because of this structure. In contrast, small molecules like water do not tend to get tangled with each other because each water molecule is separate from the others.]

o How does the example in the lab manual about steel chains and magnets connect to the visual’s diagram of how bouncy balls form? [Each steel chain is made up of hundreds of individual links, but the chains themselves are not connected to any other chain, similar to how polymers are made up of hundreds (and sometimes thousands) of smaller molecules. When you mix sodium borate with water and then add the solution to the glue, it has the same effect as adding the magnets to the steel chains. The sodium borate molecules react with the molecules of polyvinyl acetate, bonding at random places on the polyvinyl acetate molecule chains, creating cross-linked (bonded) chains.]


Transition to Experiment: 1. Watch the 2:22-minute video “Bounce Ball Reference.” The phenomenon of why some balls bounce higher than others provides the context for the lab. Constructing an explanation for one reason why this phenomenon occurs is the motivation for the experiment students design in the lesson. The video can be accessed with the video link on the KnowAtom Interactive website.

2. After watching the video, students have a brief dialogue about what they observed. Students ask questions about their observations and discuss their explanations for why they think different types of sports balls have different bounce heights. Possible back-up seed questions that teachers could consider are:

� Which ball in the video bounced the highest? � Which ball in the video bounced the lowest? � Why do you think the different balls in the video bounce

differently? � How do you think the materials the ball is made from affect its

bounce height?


� What are some steps a materials scientist might take to change how high a ball bounces?

3. Transition to the lab question: The purpose of the transition is for students to come up with a testable question related to the phenomenon that they can answer by carrying out an experiment, using the available materials.

� Divide students into teams of two. � Show the class two of the main substances (reactants) used to

make polymer bouncy balls: sodium borate (borax) and polyvinyl acetate (school glue).

� Students preview the materials available in the lab to help them form a testable question of the experiment.

� Students use Socratic dialogue to develop a question about how changing the amount of the borax used to create a polymer bouncy ball might affect the polymer’s bounce height.

� Possible questions for this lab are: o “How does the amount of sodium borate (borax) in a

polymer bouncy ball affect its bounce height?” o “How does increasing the amount of sodium borate

(borax) in a polymer bouncy ball affect its bounce height?”


Experiment: Lab 1 – Polymer Bounce

Question Once student teams have established their experiment question, students write it in their lab notebooks. For example:

� How does increasing the amount of sodium borate (borax) in a polymer bouncy ball affect its bounce height?

Students create a title for the new lab entry that is relevant to their question. In this example, a relevant lab title would be “Polymer Bounce,” but other titles can be used as well.

Research For research, students list at least three facts relevant to the experiment question, using information from the student lab manual and/or dialogue. For example:

• A polymer is a large molecule made up of many smaller molecules bonded together in a repeating chainlike pattern.

• The borax molecules react with the school glue molecules, causing the borax molecules to cross-link (bond) the school glue molecules together in a chain. This chain of molecules creates a polymer with rubbery, bouncy properties.

• If more borax is added to the reaction, more polyvinyl acetate (school glue) molecules are cross-linked together.

NOTE: Use the Who is a Scientist poster and the Scientific Process Visual to help students work through a scientific process.

SAFETY: Students must wear goggles and disposable gloves during this lab. Review the MSDS sheet for borax (sodium borate) in the appendix in the back of your binder and chemical safety information with the class from page 40 (teacher background) prior to starting the lab.


Hypothesis Students form their own hypothesis and record it in their lab notebooks. For example:

• “Increasing sodium borate in a polymer increases its bounce height.”

• “Increasing sodium borate in a polymer decreases its bounce height.”

• “The amount of sodium borate in a polymer has no effect on its bounce height.”

Checkpoint #1: After Question, Research, and Hypothesis As teams are ready, they should check in with the teacher to review their question, research, and hypothesis. Do the lab notebooks of both team members match and meet expectations? Can both students within the team explain their reasoning? If not, ask for areas of clarification or correction before they advance further. Not all teams will arrive at the lab check-points at the same time, so teams independently receive the go-ahead to move on in their lab after they have made the necessary modifications. At this point in the year, student lab notebooks entries within the class will most likely have the same question, but variations from team to team in the remaining steps of the process are expected and encouraged.

Teacher Tip: Checkpoints are opportunities for formative assessment in labs.


Summarize Experiment � Stand by the materials stations and explain the general

amounts each team can use. (Students will have enough materials to make two polymer bouncy balls.)

� Students work in teams to develop a summary of the experiment, which they record in their lab notebooks.

� Summaries should note the independent and dependent variables, constants, and a control (when applicable) in the experiment. For example o “Our experiment will compare the bounce height of two

polymers, made with different amounts of sodium borate (borax), for five separate trials when dropped from the same height above the ground. The constants in the experiment are the amounts of polyvinyl acetate (school glue) and water used to make each polymer ball. The independent variable in the experiment is the amount of sodium borate in each polymer and the dependent variable is the bounce height of each polymer. There is no control in this experiment.”

Checkpoint #2: After Experiment Summary As teams are ready, they should check in with the teacher to review the experiment summary of their lab. Do the lab notebooks of each team member match and meet expectations? Can students explain their reasoning? The summary should not include a detailed procedure or material quantities. Students describe what data will be collected to serve as

evidence to address the lab question. The summary should include the basics of the data to be collected, the number of trials students will conduct, the independent and dependent variables, and the parts of the experiment they will keep constant in each test or trial.


List Materials and Procedures Students list materials and relevant safety precautions in their notebooks.

• 60 milliliters of warm water • 40 grams of polyvinyl acetate

(school glue) • 15 grams of sodium borate

(borax) maximum • 4 plastic cups (3.5 oz) • 2 craft sticks • 2 drops of food coloring

(1 per color) • 2 plastic cups (30-mL) • 1 plastic spoon • 1 measuring tape

Due to the precision required in this experiment, students will not derive steps of the set-up procedure on their own. For this reason, the set-up procedure is facilitated by the teacher. A copy master of the facilitated set-up procedure is located at the end of the lesson (before the blank data tables on page 82). Distribute a copy of the facilitated set-up procedure for each student to add to their lab notebook under ‘procedure.’ Students think through and discuss the set-up procedure in their teams to make sure they understand it before developing their own test procedure. Polymer Set-up Procedure:

1. Add 20 grams of school glue (polyvinyl acetate) to two 3.5-oz. plastic cups. Use food coloring to color each glue sample a different color.

2. Add 30 milliliters of warm water to the remaining two 3.5-oz. plastic cups.

• 1 digital scale • masking tape (shared)

Safety

• goggles • disposable gloves

*Borax solution and powder must be kept away from eyes and skin. It is not to be ingested or inhaled. Goggles and disposable gloves must be worn.


3. Make Polymer 1: a. Choose a quantity of sodium borate (in grams) to make

Polymer 1. This quantity must be between 1 and 10 grams total. Record this quantity here: _______________ grams.

b. Measure your chosen amount of sodium borate and add it to one of the warm water cups. Mix to dissolve the sodium borate and form a solution (Solution 1).

c. Add 10 milliliters of Solution 1 to one of the polyvinyl acetate cups to create Polymer 1. Wait 15 seconds, then stir with a craft stick until it is combined. Knead the polymer into a ball, then let the ball rest for 1 minute.

4. Make Polymer 2: a. Choose a different quantity of sodium borate (in grams) to

make Polymer 2. This quantity must be different than Polymer 1: not less than 1 gram and no more than 10 grams. Record this quantity here: _______________ grams.

b. Measure your chosen amount of sodium borate and add it to the second cup of warm water. Mix to dissolve the sodium borate and form a solution (Solution 2).

c. Add 10 milliliters of Solution 2 to the second cup of polyvinyl acetate to create Polymer 2. Wait 15 seconds, then stir with a craft stick until it is combined. Knead the polymer into a ball, then let the ball rest for 1 minute.

Teams develop a standardized list of steps for their test procedure. The procedure may vary from team to team depending on approach. Student procedures should include a level of detail comparable to this example procedure:

Polymer Test Procedure:

1. Drop Polymer 1 from 90 centimeters above the ground and measure its bounce height.

2. Repeat Step 1 for 4 more trials. 3. Repeat Steps 1-2 with Polymer 2.


Scientific Diagram Students draw a titled scientific diagram of their experiment system-in-progress. All materials should be labeled. For example:

Polymer Bounce Experiment Diagram

Checkpoint #3: After Materials and Procedure As teams are ready, they should check in with the teacher to review the material and procedure steps of their lab. Are the materials and procedure in vertical lists and quantities included with all materials? Do teams understand the facilitated procedure? If not, clarify expectations. Students make corrections or any modifications and return to the checkpoint for the go-ahead.


Data

� Teams collect the materials from the pick-up stations to carry out their experiment. Photocopy and distribute blank data tables and graphs to save time (optional).

� Students record data in their data tables as the experiment progresses.

� Students then create a line graph to compare the average bounce height of each bouncy ball (dependent variable on the y-axis) with increasing amounts of sodium borate (independent variable on the x-axis). *Students can round the data to the nearest whole number (optional).

Checkpoint #4: After Scientific Diagram As teams are ready, they should check in with the teacher to review their lab scientific diagram. Are the diagrams complete? Diagrams should be titled and materials labeled. If complete, students pick up blank data tables and graphs to tape inside their lab notebooks and then proceed to collect the materials needed to conduct their experiment after meeting at this checkpoint.

NOTE: Teams will need to determine the role of each team member when dropping and recording bounce height measurements. One team member can drop the polymer while the other assesses the approximate height of the first rebound. The masking tape can be used to mark the drop height distance above the ground. It can also be used to mark centimeter increments as a reference for determining bounce height. Teams may wish to practice measuring the polymer ball bounce heights for several trials before collecting data.


* Sample data represent one possible outcome.

Table 1: Comparing Bouncy Ball Polymer Rebound Height From a 90-cm Drop Height

Polymer 1 Polymer 2 mass _21.0 g

color green

sodium borate _1.0_ g

mass _20.4 g

color yellow

sodium borate _5.0_ g

Trial Bounce Height (cm)

Bounce Height (cm)

1 15 30 2 15 30 3 17 45 4 17 25 5 16 35

Average 16 33

0 2 4 6 8

10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40

0 1 2 3 4 5 6

Aver

age

Poly

mer

Bou

nce

Hei

ght (

cm)

Sodium Borate (g)

Graph 1: Comparing Rebound Height of Polymer Balls Made with Different Amounts of Sodium

Borate


Conclusion Each student writes a conclusion that summarizes their findings and tells how the data did or did not support the hypothesis. For example: “Our hypothesis that the amount of sodium borate in a polymer has no effect on its bounce height is false. Our data show that Polymer 2, made with a 5.0-gram solution of sodium borate, bounced 17 centimeters higher on average than Polymer 1, which was made with a 1.0-gram solution of sodium borate. Even though both polymer balls were close in mass, Polymer 2 had more sodium borate molecules available to cross-link (bond) with polyvinyl acetate molecules, making it firmer and bouncier than Polymer 1, which was formed with less sodium borate and felt more bendable and less firm. We can conclude that increasing sodium borate does increase the bounce height of bouncy ball polymers.”

Wrap-Up: 1. Students construct explanations and engage in argument from evidence: Students share and discuss their results from the experiment. For example:

Final Checkpoint: After Data and Conclusion As teams are ready, they should check in with the teacher to review the data and conclusion steps of their lab. One team member reads the team’s conclusion aloud to you while you review the other team member’s lab notebook. Do they restate the hypothesis? Have they made a true/false/inconclusive claim? Look for key data points that students used to form their conclusion. Is it clear? Is it persuasive? Do the data support the claim? If the results are contrary to their research, what might be responsible? How could they test for that in the future?


• One team presents their conclusion to the class. Do the key data they used support their conclusion?

• Were the data consistent with all teams in the class? If not, what may have caused some teams to have different data? [Answers will vary. Ask students to compare their results and analyze possibilities for any differences, such as a difference in sodium borate amounts, or carrying/developing the procedure.]

• Did you experience any challenges in conducting this experiment? If so, what were they? [Answers will vary. Challenges are a part of conducting experiments, and discussing them can help students think through their process, comparing their method with other student teams. For example, measuring the height of the bouncy ball can be tricky. It can be helpful to develop a system to coordinate measuring the bounce height data before beginning the data collection.]

• What pattern did you notice in the data that indicated a relationship between the height of the bounce and the amount of sodium borate used? What causes this relationship? [The more sodium borate that was used, the higher the bouncy ball bounced. This is because more sodium borate molecules are available to cross-link (bond) with the polyvinyl acetate molecules. This structure made the polymer with more sodium borate firmer and bouncier.]

2. Connect to phenomena: Students make connections between their experiment results and the phenomenon of how some sports balls bounce higher than others.

• As a class, students discuss how their experiment results connect back to the video they watched at the beginning of the lesson and the question of how a materials scientist could make a ball bounce higher. Possible connections include: o The materials a ball is made of affect how high it bounces.


o Materials scientists can design new substances that bounce higher by changing the amount of reactants or substances used to form the ball.

• How could you tell that a chemical reaction took place when the school glue (polyvinyl acetate) and borax (sodium borate) were mixed? [Before the two substances were mixed, they each had specific properties. For example, school glue is a sticky liquid, and borax is a solid powder. After they were mixed, the new substance had different properties, becoming a bouncy, stretchy solid.]

• Given what you know about the conservation of mass, what can you conclude about the mass of the reaction that caused the formation of the bouncy ball? [The same number of atoms of each of the elements in the reactants (polyvinyl acetate, sodium borate, and water) was present at the end of the reaction that formed the polymer bouncy ball.]

• Student discussion may lead to new questions. Students can reason through these new questions, using evidence from their model, experiment results, or lab manual. Possible extension questions include: o Why would the same polymer ball bounce higher if you

throw it down with a lot of force compared to if you dropped it gently?

o Why does a ball such as a baseball not bounce very high, while polymer balls do?

o What is the relationship between kinetic energy and sound?


Unit 1: Lesson 2 – Example Lab Notebook This complete lab notebook entry is intended to be used as an

exemplar for teacher use only. It is not intended for student use.


Unit 1: Lesson 2 – Facilitated Procedure Polymer Set-up Procedure (facilitated):

1. Add 20 grams of school glue (polyvinyl acetate) to two 3.5-oz. plastic cups. Use food coloring to color each glue sample a different color.

2. Add 30 milliliters of warm water to the remaining two 3.5-oz. plastic cups.

3. Make Polymer 1: a. Choose a quantity of sodium borate (in grams) to make

Polymer 1. This quantity must be between 1 and 10 grams total. Record this quantity here: _______________ grams.

b. Measure your chosen amount of sodium borate and add it to one of the warm water cups. Mix to dissolve the sodium borate and form a solution (Solution 1).

c. Add 10 milliliters of Solution 1 to one of the polyvinyl acetate cups to create Polymer 1. Wait 15 seconds, then stir with a craft stick until it is combined. Knead the polymer into a ball, then let the ball rest for 1 minute.

4. Make Polymer 2: a. Choose a different quantity of sodium borate (in grams) to

make Polymer 2. This quantity must be different than Polymer 1: not less than 1 gram and no more than 10 grams. Record this quantity here: _______________ grams.

b. Measure your chosen amount of sodium borate and add it to the second cup of warm water. Mix to dissolve the sodium borate and form a solution (Solution 2).

c. Add 10 milliliters of Solution 2 to the second cup of polyvinyl acetate to create Polymer 2. Wait 15 seconds, then stir with a craft stick until it is combined. Knead the polymer into a ball, then let the ball rest for 1 minute.


Unit 1: Lesson 2 – Blank Data Table and Blank Graph

Table 1: Comparing Bouncy Ball Polymer Rebound Height From a 90-cm Drop Height

Polymer 1 Polymer 2 mass ______ g

color

sodium borate _____ g

mass ______ g

color

sodium borate _____ g

Trial Bounce Height (cm)

Bounce Height (cm)

1 2 3 4 5

Average

0 2 4 6 8

10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40

0 1 2 3 4 5 6

Aver

age

Poly

mer

Bou

nce

HEig

ht (c

m)

Sodium Borate Amount (g)

Graph 1: Comparing Rebound Height of Polymer Balls made with increasing amounts of Sodium


Objective: Students model a basic manufacturing process to create plastic keychains for a factory, and then make improvements to the manufacturing process to decrease waste and improve efficiency and output.

Materials:

Consumable A. Goggles – 1 per student B. “Manufacturing Processes Investigation” – 1 per student (lab manual) C. “Keychain Manufacturing Process Cards” (template set) – 1 set per team (7 sheets per set) D. Safety and Quality Control Check Sheets – 8 per team E. Large paper clips – 2 per team F. Small paper clips – 10 per team G. Plastic “discard” cups – 1 per team H. Plastic trays – 1 per team I. Glue gun glue – 8-10 sticks per team J. Paper towels – teacher provides (not shown)

Non-Consumable K. Digital scales –1 per team L. Rubber molds – 3 per team M. Metal washers – 10 per team N. Stopwatches – 1 per team O. Graduated cups and measuring containers – shared P. Manufacturing Visual – (not shown)

Lesson 3: Manufacturing Processes

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Q. Making Crayons Visual – (not shown) Teacher Tool Kit R. Scissors – 1 per team S. Glue guns – 1-2 per team T. Extension cords – teacher use U. Power strips – teacher use V. Masking tape – shared W. Permanent markers – 1 per team Teacher Preparation:

• Download the visuals from the KnowAtom Interactive website. • Arrange several pick-up stations for teams to pick up materials

to use at their desks. For example: o Pick-Up Station 1: Keychain Manufacturing Process Cards o Pick-Up Station 2: rubber molds and plastic trays o Pick-Up Station 3: paper clips (small), scissors, plastic

“discard” cups, and permanent markers o Pick-Up Station 4: large paper clips, metal washers, masking

tape, stopwatches, digital scales, and Safety and Quality Control Check sheets

• Arrange a cold water collection station. This station should have graduated cups and several graduated measuring containers filled with cold water. The water will be used to cool the hot glue in the rubber molds. Keep this station separate from the hot glue station.

• Arrange several hot glue stations using the extension cords and power strips. To prevent crowding, separate the stations in the classroom. Two students from each team of six will need to access the glue station. For safety, keep the glue station separate from the water station and water use in this lesson.

R S

T U

V W



• Students read the Section 3 of the student lab manual. At the beginning of the school year the lab manual can be read aloud in class. This will help to model for students how to read closely for understanding. For example: o Pause at different key points during the reading to

emphasize connections between examples in the reading and broader concepts. For example, ask why a certain example was used to support the reading’s main point.



Socratic Dialogue:

Block 3-1: Introduction to Manufacturing 1. Students watch the video about the Crayola manufacturing process to begin the Socratic dialogue.

� The video can be accessed with the video link on the KnowAtom Interactive website.


2. After watching the video, students have a Socratic dialogue about what they observed. Socratic dialogue should begin with a student question. The following sequence is one potential progression of big ideas. However, these big ideas are part of a dynamic, three-dimensional context so students may progress through them in different ways. While the big ideas are an important part of the discussion, teachers shouldn’t expect the dialogue to follow the same linear progression as this example sequence. 3. Consider displaying Manufacturing Visual as a backdrop to Big Idea 8.

� Big Idea 8: Manufacturing builds on scientific knowledge about the relationship between matter’s structure and its properties. Manufacturing is an operation that transforms raw materials—the basic materials from which a product is made—into a finished product. Possible back-up seed questions that teachers could consider are: o Why is manufacturing important in today’s society?

[Manufacturing is what builds all of the “stuff” that surrounds you, from the nails and screws that hold your desk together to your cell phone, your clothes, and your car.]

o Why is it important to know about the properties of different materials in manufacturing? [Properties make certain materials better for specific functions than other materials. For example, nylon is durable, flexible, and elastic, which makes it good for a wide range of products, including toothbrushes, women’s stockings and other


clothing, carpets, hoses, parachutes, racket strings, and dental floss.]

4. Consider displaying Making Crayons Visual as a backdrop to Big Idea 9.

� Big Idea 13: Process is an important part of manufacturing because a process is any series of steps designed to meet a goal. Manufacturers need to follow set processes because they want to make sure that the goods they produce meet certain design and safety standards. Possible back-up seed questions that teachers could consider are: o Why is it important to follow a set process that is

sequential (the first step has to happen before the second step, which has to happen before the third step, etc.)? [Each step in a manufacturing process has a very specific function, and it prepares the materials used for the next step. For example, when making crayons, the paraffin wax cannot be mixed with the color pigments when it is still solid, so mixing cannot happen before melting.]

o What would happen if someone forgot the mixing step? [The color pigments are what give the crayons their different colors. If this step is left out, all of the crayons would be the same color of white.]

o Why does the forming step come when it does in the process? (Forming is a manufacturing process that changes the shape of the material into a specified form.) [The wax/pigment mixture needs to be in its melted form so that it can be poured into the molding machines, which


shape the mixture. Once the wax has hardened, it can no longer be poured.]

o What is the role that cold water plays in the forming process? [Cold water cools the wax down, which helps to speed up the process of the wax cooling in the mold. When the wax mixture cools, it hardens in the shape of the mold.]

o What is the relationship between forming and extrusion? [Extrusion is a manufacturing process in which a material is put into a chamber and pressed out through a hole (also called a die). The hardened wax is extruded from the mold.]

o Why is extrusion an example of a physical, not a chemical, process? (Extrusion is a physical process because it doesn’t change the chemical structure of the wax mixture. In chemical processing, the chemical structure of the material is changed.]

o What is the role of quality control in a manufacturing process? [Quality control is a process that reviews the fitness of production by comparing items produced to a production standard. This process includes product inspection, where someone examines the final product for unacceptable defects, such as cracks. Each crayon is inspected for breaks and chips, as well for bubbles, which can appear if mixing has not been complete.]

Investigation: 1. Divide the class into many teams of six. If you have an uneven number of students in your class, teams of seven students will work as well.

SAFETY: Students should wear goggles during this activity. Review how to safely use glue guns and that glue guns should not be used near water.


2. Stand by the pick-up stations to explain how the materials will be used and the amount each team will receive. Teams should go to stations to collect the materials they will use at their desks. Pick-Up Station 1:

• Keychain Manufacturing Process Cards – 1 set per team (7 sheets per set)

• “Manufacturing Process Investigation” (lab manuals) – 1 per student

Each team will: � Review the scenario outlined on the Manufacturing Process

Investigation: The ABC Factory is manufacturing a new plastic keychain from raw polymer material. In order to create the product, employees have designed a manufacturing process that involves the following steps:

1. Extruding and Forming – A solid, raw piece of plastic polymer is heated into a liquid and then extruded into molds.

2. Separating the Cast(s) – The molded plastic (casts) are cooled and removed from the mold(s).

3. Assembling – Two pieces of the cooled, molded plastic are glued together with a metal keychain hook.

4. Cutting – The rough edges of the plastic keychain are trimmed.

5. Finishing – The plastic keychain is colored. 6. Safety and Quality Control – The finished keychain hook

is tested for safety defects and the product is examined to ensure it meets quality standards.

� Review the procedures on the Keychain Manufacturing Process Cards with your team, including how the materials are used in each step of ABC Factory’s process. Decide who will be responsible for carrying out each step of the process.


NOTE: Not all team members will be active during the first few minutes of assembling the first keychain. All members will be active once a workflow is established in the team and the keychain materials are passed through the assembly line.

Hot Glue Stations: • hot glue guns – 1-2 per team • glue sticks – shared bag

Pick-Up Station 1:

• rubber molds – 3 per team • plastic trays – 1 per team

Pick-Up Station 2:

• small paper clips – 10 per team • scissors – 1-2 per team • plastic “discard” cups – 1 per team • permanent markers – 1 per team (assorted colors)

Pick-Up Station 3:

• large paper clips – 2 per team • metal washers – 10 per team • masking tape – shared • stopwatches – 1 per team • digital scales – 1 per team • Safety and Quality Control Check Sheets – 10 per team (each

page contains two check sheets) Explain that each team will:

� Collect the materials for the manufacturing process as detailed on the Keychain Manufacturing Process Cards. Set up an assembly line formation within your team to organize the flow of materials from Step 1

Safety: Glue gun stations should be kept apart from the “Separating the Cast(s)” station because that station uses water.


(extruding and forming) through Step 6 (Safety and Quality Control) according to the directions on the Keychain Manufacturing Process cards. The team member(s) responsible for Safety and Quality Control will be responsible for timing the process from start to finish.

� Use ABC Factory’s improved keychain manufacturing process to create four keychains total for Batch 1. Once four keychains are complete, the batch is complete. (See the individual Keychain Manufacturing Process Cards for the detailed instructions for each step of the manufacturing process.)

� Analyze ABC Factory’s Keychain Manufacturing Process 1. Record the Batch 1 Quality Control Data in the space below

(given by the Safety and Quality Control team member).

As a team, evaluate the quality control data. Describe how you could improve ABC Factory’s manufacturing process to decrease the time it takes to produce a single keychain, while reducing waste and improving the quality of the keychains. TIP: This may involve combining or reordering steps, and/or having one person carry out two steps, or two people carry out one step together, etc.

2. Draw a flow chart diagram that details the steps of the improved manufacturing process for ABC Factory in the empty space on the activity sheet. Modify the Keychain Manufacturing Process Cards according to the improvements your team wants to make.

Batch 1: Quality Control Data # Keychains attempted: ________________________

# Keychains completed: _______________________

Total time to complete the batch: _________________________ minutes

Average time to complete one keychain in this batch: ________________________ minutes

Total mass of batch waste (in “discard” cup): __________________ grams.


� Carry out the Improved Keychain Manufacturing Process 1. Set up the assembly line formation within your team based

on your new and improved keychain manufacturing plan for ABC Factory (detailed in the flow chart you created in the previous section and the modified Keychain Manufacturing Process Cards). The team member(s) responsible for Safety and Quality Control will be responsible for timing the process from start to finish.

2. Use ABC Factory’s keychain manufacturing process to Create four keychains total for Batch 2. Once four keychains are complete, the batch is complete.

� Analyze ABC Factory’s Improved Keychain Manufacturing Process 1. Record the Batch 2 Quality Control Data in the space below

(given by the Safety and Quality Control team member).

As a team, evaluate the quality control data. Describe how the improvements to ABC Factory’s keychain manufacturing process positively or negatively impacted the following: the average time it took to produce each keychain, the amount of waste produced, and the quality of the keychains, compared to Batch 1.

3. Teams collect their materials from the pick-up stations in order to start the activity. Circulate the classroom to monitor team processes and to help students during the improvement phase of the activity.

Batch 2: Quality Control Data # Keychains attempted: ________________________

# Keychains completed: _______________________

Total time to complete the batch: _________________________ minutes

Average time to complete one keychain in this batch: ________________________ minutes

Total mass of batch waste (in “discard” cup): __________________ grams.


Wrap-Up: 1. Students construct explanations: Students share and discuss team improvements to the process. For example:

• What were some ways that teams changed their process to be more efficient and reduce waste? [Answers will vary. Have students explain why they decided to make the changes they did, and how they think those changes affected their process.]

• Were there challenges in meeting the quality control standards? [Answers will vary. Have students think through ways they modified their approach if they had trouble in the beginning.]

• What would happen to the process if one step is suddenly unavailable (for example if a machine breaks down)? [The entire process will be affected because each step has an important role to play in the overall process.]

• Why is using a process that involves multiple steps/people useful for companies manufacturing large quantities of products? [It makes it much more efficient when manufacturing large quantities of products. If one person were in charge of every step in the process, it would take a lot longer to complete the same number of products as when an assembly line is used.]

2. Students engage in argument from evidence: Students have a dialogue about how the manufacturing process transformed the raw polymer material into a finished product. For example:

• What were the properties of the raw polymer material? [It was solid glue, so it was opaque and hard, but also somewhat flexible.]

• How did extrusion change the shape of the material? [When the glue was extruded from the glue gun, it was heated so it came out in a narrow stream of liquid glue.]


• What was the role of molding in your process? [The molds shaped the material into the desired shape, so each mold was uniform in size and shape.]

• Why was assembly important? [The mold created one half of the keychain, so both halves had to be assembled together. The metal hook (paperclip) also had to be attached.]

• Why was quality control an important step? [Quality control ensures that the final products all meet the desired specifications.]


Name:_________________________________________________ Date:_______________

Unit 1: Molecules to Materials Vocabulary Check

Part I: Circle the best answer for questions 1-5 below.

1. A(n) _____ _____ is the smallest piece of matter that has the properties of an element.

A. material B. proton C. molecule D. atom

2. Chemical energy is an example of _____ _____ because it is energy stored in the bonds holding together atoms and molecules.

A. conservation of mass B. scientific process C. kinetic energy D. potential energy

3. A reactant has different properties from the product because the atoms of the reactants are rearranged into a new substance in a(n) ____ .

A. chemical reaction B. conservation of mass C. experiment D. molecule

4. Causing a substance to change state by adding thermal energy to it is an example of a __ _________because it doesn’t affect the chemical structure of the substance.

A. physical change B. chemical change C. chemical reaction D. property

5. ___ ____ is the motion of atoms and molecules in a substance as its temperature increases.

A. Endothermic energy B. Chemical energy C. Thermal energy D. Potential energy


Part II: Write the answers to questions 6-8 below. 6. How is a substance’s chemical energy related to its atomic structure? _____________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 7. How do scientists use properties to determine whether a chemical reaction has taken place? _____________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 8. Why is a polymer a kind of molecule? How is it different from a molecule such as water? _____________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________


Name:_________________________________________________ Date:_______________

Unit 1: Molecules to Materials Concept Check

Part I: Circle the best answer to each question. 1. Rubber is a bouncy, stretchy polymer made up of many connected smaller molecules. It can be naturally occurring or produced by humans. Which of the following statements best describes the relationship between rubber’s structure and its properties?

A. Rubber’s properties cause rubber to have the structure that it does.

B. Rubber’s structure causes rubber to have the properties that it does.

C. There is no connection between rubber’s structure and its properties.

2. When vinegar, baking soda, and water are added to powdered milk, a glue is produced. What happened to cause this change?

A. A chemical reaction rearranged the molecules of the vinegar, baking soda, water, and milk to produce a new substance with different properties.

B. A physical change caused the vinegar, baking soda, water, and milk to form glue.

C. The molecules that made up the vinegar, baking soda, water, and milk disappeared, and new molecules of glue were created.

3. Which of the following statements is true?

A. New atoms are created during chemical reactions, which is how new substances are created.

B. Atoms can be destroyed during a chemical reaction. C. Whenever atoms interact with one another, no matter how

they are rearranged, the total mass stays the same.


Part II: Read the Pizza Dough scenario and then answer the questions that follow.

Word Bank mass - the measure of the amount of matter that makes up an object or substance; measured in grams (g)

Pizza Dough

Raquel decided to make homemade pizza dough for the first time. She measured and combined several ingredients to make the pizza dough flour mixture. She then used a scale to measure the mass of the pizza dough flour mixture and the mass of the water before mixing them together. After mixing the ingredients together, she formed a ball of dough, placed it in a bowl, and covered it in plastic wrap. She let the pizza dough rise for one hour. After an hour, the ball of pizza dough was larger. Raquel was curious if the mass of the pizza dough had changed since she could see that the dough was larger. She measured the mass of the pizza dough on her scale and was surprised to find that it was the same as the mass of the ingredients before they were mixed together. She was curious why the size of the dough increased without the mass increasing.

The next day, Raquel shared her observations with her science class. Some of the students thought that the mass of the pizza dough

size of initial dough size of dough after 1 hour


should be more than the mass of the ingredients before they were mixed together. Other students thought the mass would stay the same. To investigate what happened with the dough, Raquel’s science class decided to conduct an experiment to help them answer their questions. Raquel’s teacher asked the class to think of a question they could ask about the masses of substances before and after they are mixed together, so the class came up with the following question for their experiment: When two substances combine, how do their masses before they are combined compare with their mass after they are combined? Raquel’s science teacher gave each team of students a scale, a bottle with a cap, a small plastic cup, liquid, and white powder to investigate their question. Raquel and her team took the materials and designed an experiment to compare the mass of the water and powder before and after they are combined for three separate trials.

Experiment Materials


Make a Prediction

When two substances combine, how do their masses before they are combined compare with their mass after they are combined? 1. Write a prediction for the question in the spaces below. Tip: This question is most similar to the hypothesis in the scientific process.

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2. Explain your prediction using information from the story and what you already know about what happens to substances when they combine to support your prediction.

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Testing the Prediction Raquel and her team designed and carried out the following procedure for their experiment:

1. Pour water into the bottle up to the “fill” line. Measure the mas of the test tube, cap, and water.

2. Add 5 grams of the white powder to the bottle with the water and quickly seal the bottle with the cap to close the system.

3. Gently shake the bottle to mix the substances together. Measure the final mass of the system (bottle with bottle cap and the mixture and the empty small cup).

4. Empty the bottle and discard the mixture. Repeat Steps 1-4 for two more trials, using fresh water and white powder in each trial.

Diagram Here is a diagram of Raquel’s experiment system during Trial 1 after the substances were combined in the bottle.


Data Raquel’s team collected data in Table 1 and made observations during their experiment in Table 2.

Table 1: Comparing Mass Before and After Mixing

Containers + Substances System Bottle + Cap +

Water (g)

White Powder + Small Cup

(g)

Final Mass

(g)

Initial Mass

(g)

Change in Mass

(g) Trial 1 31.2 5.2 36.4 36.4 0 Trial 2 31.8 5.2 37.0 37. 0 0 Trial 3 33.1 5.2 38.3 38.3 0

Average Change in Mass 0

Table 2: Observations

Observations of Substances

Before Mixing

Observations of Substances During

the Reaction

Observations of Substances After the

Reaction

Trial 1

The water color is clear. The white powder (solid) is white.

A gas formed. The water fizzed and bubbles rose to the top of the bottle.

The white powder dissolved in the water. The water returned to its original position in the test tube. The water has many small bubbles in it.

Trial 2

same as Trial 1 same as Trial 1 same as Trial 1

Trial 3

same as Trial 1 same as Trial 1 same as Trial 1


Analyze the Results 3. How does the investigation provide evidence that a chemical reaction took place when the white powder and water were combined? Use specific evidence from the investigation to support your answer.

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4. Look at the prediction you wrote for Question 1. Explain how the data Raquel’s team collected in their experiment did or did not support your prediction. Tip: This question is most similar to the conclusion step in the scientific process. ______________________________________________________________________________

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5. Raquel’s team was very careful to measure the mass of the substances and the containers (bottle, bottle cap, and small cup) before and after the substances we mixed together. Why did they do this? Use specific evidence from the procedure and Table 1 to support your answer. ______________________________________________________________________________

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6. One team in Raquel’s class lost the cap to their bottle, so they carried out the investigation in the same way as Raquel’s team, just without the bottle cap. However, the average change in mass for their experiment was 2.5 grams. Compare Raquel’s results in Table 1 with those of the team without the bottle cap. Explain why the average change in mass in Raquel’s team was different. Use evidence to support your answer.


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Unit 1: Appendix 1 Answer Keys

Vocabulary Check Part I 1. D. atom [An atom is the smallest piece of matter that has the properties of

an element (a substance made up entirely of one kind of atom). A molecule is a combination of two or more atoms bonded together. A proton is a subatomic particle found in the nucleus of an atom. A material is a substance that is designed to be used for certain applications.]

2. D. potential energy [Chemical energy is an example of potential energy because it is energy stored in the bonds holding together atoms and molecules. All potential energy is energy that is stored. Kinetic energy is the energy of motion. Conservation of mass refers to the theory that matter is never created or destroyed, which means that the total number of atoms does not change in a chemical reaction. Scientists follow a scientific process to answer questions using data from experiments.]

3. A. chemical reaction [A reactant has different properties from the product because the atoms of the reactants are rearranged into a new substance in a chemical reaction. Conservation of mass refers to the theory that matter is never created or destroyed, which means that the total number of atoms does not change in a chemical reaction. An experiment is a specific procedure that tests if a hypothesis is true or false. A molecule is a combination of two or more atoms bonded together.]

4. A. physical change [Causing a substance to change state by adding thermal energy to it is an example of a physical change because it doesn’t affect the chemical structure of the substance. A physical change is different from a chemical change, which rearranges the chemical structure of the substances through a chemical reaction. A chemical reaction is a process that rearranges the atoms of the original substances into a new substance that has different properties from the original substances. A property is an observable or measurable characteristic of a substance.]

5. C. Thermal energy [Thermal energy is the motion of atoms and molecules in a substance as its temperature increases. Potential energy is energy that is stored. There is no such thing as endothermic energy. In endothermic reactions, energy is absorbed from the environment]


Part II 6. [Chemical energy is a form of potential energy that is stored in the bonds

holding together atoms and molecules. Structure is the way in which parts are put together to form a whole. The structure of the molecule is directly related to a substance’s chemical energy because the bonds are what join different atoms together to form molecules.]

7. [Properties are the observable or measurable characteristics of a substance. Scientists use properties to determine whether a chemical reaction has taken place because chemical reactions rearrange the atoms of the original substances into a new substance that has different properties from the original substances.]

8. [A polymer is a large molecule made up of many smaller molecules bonded together in a repeating chainlike pattern. Unlike other molecules such as water, polymers are much larger because they are made up of smaller molecules bonded together. Polymers can have hundreds or thousands of molecules. In contrast, a water molecule is small, made up of just three atoms.]

Concept Check Part I 1. B. Rubber’s structure causes rubber to have the properties that it does.

[Rubber is a bouncy, stretchy polymer, made up of many connected smaller molecules. It is because of its structure that rubber has the properties that it does. It is the way that the molecules are structured that causes polymers to have many of the properties that they do. This question highlights the cause-and-effect relationship between properties and structure—it is the structure of matter that causes it to have the properties it does, not the other way around.]

2. A. A chemical reaction rearranged the molecules of the vinegar, baking soda, water, and milk to produce a new substance with different properties. [When vinegar, baking soda, and water are added to powdered milk, a glue is produced because a chemical reaction occurred that rearranged the molecules of the reactants to produce the glue. This is why glue has such different properties than the reactants. In a physical change, the chemical structure of the substances is not changed. Molecules never disappear or are created from nothing. Instead, they are reformed and rearranged in chemical reactions to produce new substances.]


3. C. Whenever atoms interact with one another, no matter how they are rearranged, the total mass stays the same. [Because matter is never created or destroyed, the total mass of the atoms remains the same whenever atoms interact with one another. Atoms cannot be created or destroyed in a chemical reaction.]

Part II This assessment asks students to analyze an experiment that investigates how the masses of two substances before they are combined compare with their mass after they are combined. These questions assess the Massachusetts standards 8.MS-PS1-2 and 8.MS-PS1-5. 1. By developing a prediction about how the masses of two substances before

they are combined compare with their mass after they are combined, students are partially assessed on the science and engineering practice of Asking Questions and Defining Problems. Students are also partially assessed on the disciplinary core ideas of Chemical Reactions and Structure and Properties of Matter.

o Student answer should demonstrate an understanding of how questions guide an investigation. In this example, the prediction should demonstrate that student understands what the investigation is seeking to show. It should also demonstrate an awareness of the scientific principles that will help to answer the question. The prediction is most similar to the hypothesis in the scientific process, which is a clear and concise statement that can be proved true or false, and it should be a declarative sentence that does not include personal pronoun words like “my” or “I think.” For example:

o The masses of the two substances before mixing (reactants) will be greater than the total mass of the product after combining.

o The masses of the two substances before mixing (reactants) will be less than the total mass of the product after combining.

o The masses of the two substances before mixing (reactants) will be the same as the total mass of the product after combining.

2. Students are partially assessed on the disciplinary core idea of Chemical Reactions and Structure and Properties of Matter as they explain their


prediction, using what they know about atoms, chemical reactions, and the conservation of matter.

For example: Matter is never created or destroyed. Regardless of the type of change that occurs when two substances are mixed, the total number of atoms remains the same.

3. By using the data provided in the table to answer the question of how the investigation provided evidence that a chemical reaction took place when the white powder and water were combined, students are partially assessed on the science and engineering practice of Analyzing and Interpreting Data, as well as the disciplinary core idea of Structure and Properties of Matter. o Student response should include one key piece of data, either

numerical or observational, from the investigation to support the response. The response should reflect that students can reference and explain key data points from the data table. Response should indicate that a chemical reaction took place between the white powder and the water because the white powder dissolved in the water and a gas formed. For example: The investigation demonstrated that a reaction took

place because a new substance was produced that had new properties. The data showed that the reaction produced bubbles in the water and the water fizzed, indicating that a gas was produced.

4. By using the data to analyze their prediction, students are partially assessed on the science and engineering practice of Constructing Explanations and Designing Solutions as they explain how the mass of two substances before mixing is equal to the total mass after mixing, using the change in mass as evidence.

o Student response should reflect that the student correctly analyzed their prediction based on the data provided. For example: “The prediction that the masses of the two

substances before mixing (reactants) will be the same as the total mass of the product after combining was true. The data showed that the initial mass of the system was the same as the final mass of the system after the two substances were mixed together. The data showed that in all three trials, matter was conserved.”

5. Student answer should demonstrate an understanding of controlled experiments and the system being tested. For example:


o Raquel’s team measured the mass of the substances and the containers (bottle, bottle cap, and small cup) that held the substances before and after the substances were mixed together the same way for each trial because the substances and the containers formed a system in the experiment, and Raquel’s team needed to conduct a controlled experiment so their results would be valid. If the mass of the containers was not included in the final mass of the system, the results would be inaccurate.

6. By analyzing a slightly different scenario, students are partially assessed on the science and engineering practice of Obtaining, Evaluating, and Communicating Information, as well as the disciplinary core idea of Chemical Reactions. Student answer should demonstrate an understanding of why an experiment with an open system results in different data from a closed system. For example:

o The team in Raquel’s class that lost its bottle cap had different results, with an average change in mass of 2.5 grams, compared to Raquel’s team of no change in mass. This occurred because without the bottle cap, the system was open, allowing the gas (matter) produced in the reaction to escape into the environment. For example, if a gas is produced, it will fill whatever space it is in. This is impossible to measure, and it can explain the difference in data between Raquel’s team and the other team.


Lab Manual Answer Key Section 1 Review MC1. C. They break and re-form chemical bonds. [All chemical reactions break

and re-form chemical bonds. In this process, the atoms that make up the original substances are rearranged into a new substance that has different properties from the original substance. Chemical reactions never create new elements or destroy the atoms of reactants to produce the new products because matter is never created or destroyed. Instead, atoms are rearranged to form new substances with different properties. Not all chemical reactions cause liquid substances to turn into a gas. While that sometimes occurs, it depends on the kinds of reactants combining in the chemical reaction.]

MC2. A. A chemical reaction changed the molecules making up the logs to produce ash and other matter, likely gases. [When a bonfire burns the logs, a chemical reaction takes place that breaks down the molecules that make up the logs and rearrange them into new substances, including the ash and gases (such as carbon dioxide). Even though we cannot see the gases, they are still present and therefore matter has not been destroyed. It is not a physical change because in physical changes, the chemical structure of the substance—and therefore its properties—doesn’t change.]

CT1. [Materials scientists are interested in the structure of materials at the molecular level because materials act differently depending on the kinds of atoms that make them up, how those atoms are bonded together in molecules or compounds, and their structure.]

CT2. [The properties of the synthetic material designed by humans to mimic gecko feet include its adhesiveness, or “stickability,” while being able to attach and detach easily. This allows this material to stick to various surfaces without getting stuck permanently, like glue would.]

CT3. [A synthetic material that mimics geckos’ feet could fulfill various societal needs. For example, scientists are thinking about applications as common as wigs and toupees that remain in place, and as cutting edge as robots that can catch space junk (such as satellites that are no longer working).

CT4. [Many materials scientists think the creation of the Periodic Table of Elements was the most important event in their field because it arranges all of the known elements in an informative way. People who are familiar with how the table is put together can quickly determine a


significant amount of information about an element because natural patterns appear within groups of elements. Understanding the properties of the different elements is essential for materials scientists, who need to know about an element’s properties, as well as how substances’ properties change in various chemical reactions.]

CT5. [The products of a chemical reaction have different properties from the reactants because the atoms and molecules of the reactants have been rearranged in the chemical reaction. A substance’s properties are determined by the structure of the atoms and molecules that make it up, so when those atoms and molecules are rearranged, properties also change.]

Section 2 Review MC3. B. Cellulose is made up of many smaller molecules bonded together.

[Cellulose is a natural polymer found in plants. Because it is a polymer, we know that it is a molecule made up of many smaller molecules bonded together. Because cellulose occurs naturally, it is not synthetic. However, it is made up of atoms because it is matter. All molecules are made up of two or more atoms bonded together.]

MC4. A. The way Teflon’s atoms are bonded together makes it resistant to chemicals. [Teflon’s structure is related to its non-stick function in cooking pots because the way Teflon’s atoms are bonded together makes it resistant to chemicals.]

CT6. [A property of polymers that is a result of their long-chain structure is their strength because the long, connected strings of molecules make the polymer strong.]

CT7. [Answers will vary. For example, polymers are difficult to dispose of because they are not biodegradable, which means micro-organisms can’t break them down. Many polymers can be recycled, and certain chemicals added to polymers can make them more biodegradable.]

Section 3 Review MC5. D. clothing [Clothing is not a raw material. Raw materials are the basic

materials from which a product is made. Clothing is an example of a final product, which is made from different raw materials, including cotton and nylon.]

MC6. B. a physical process [The process of cutting the metal, eliminating parts of the metal that aren’t necessary, is an example of a physical process because cutting doesn’t change the chemical structure of the material.


Because of this, it doesn’t change the material’s properties. In a chemical process, in contrast, the properties may change because it changes the particulate structure of a material. Assembling is a process in which all of the components are assembled into a whole product. Finishing is a process when additional features are added to complete the look of the product.]

CT8. [It is important for manufacturers to follow set processes because they want to make sure that the goods they produce meet certain standards. The process helps ensure that every step is properly followed and the end products are equal in design, durability, and safety.]

CT9. [Answers will vary. Quality control is the process that reviews the fitness of production by comparing items produced to a production standard. It can include checking to make sure all parts work as they are designed to, and that they are safe to use.]

CT10. [Answers about the advantages and disadvantages of human control of manufacturing processes versus machine control of these processes will vary depending on student research. For example, it depends on the specific industry and the specific process. Generally speaking, however, some advantages to machines performing manufacturing processes include greater efficiency because production takes less time when done by a machine. Machines are also more accurate and more reliable because there is less opportunity for human error. It can also be cheaper for the company because fewer employees are needed to get the job done. However, there are some disadvantages. For example, having all machines means there is less versatility and flexibility, because the machine can generally perform only the tasks it was designed to perform. There is also a large upfront cost to purchase the machine, and large unemployment because so many fewer people are needed.


Unit 1: Appendix 2 Common Core Connections

KnowAtom lessons cover many Common Core ELA and math standards in the lab manual, discussion, and hands-on activities. The lab manual is designed to further connect science content to other disciplines with assignments that can be used as homework or in-class. The lab manual highlights one ELA standard: ELA (page 11 of lab manual) Reading: Informational Text – Grade 8 Key Ideas and Details

• ELA-Literacy.RI.8.3: Determine a central idea of a text and analyze its development over the course of the text, including its relationship to supporting ideas; provide an objective summary of the text.

Students read an account of the Materials Library in London, England. Students should understand that materials scientists are interested in materials for their properties and the societal need that they can fill. A new trend is libraries that house and exhibit the vast array of materials that exist, as a place to describe the many properties and uses of these materials. Example Answer Key: 1. [The central idea is that as materials science becomes more innovative, materials libraries are emerging to try to collect and display the many unusual materials that have been created.] 2. [The text uses many examples of the types of materials, including a swatch of the world’s blackest black, 25 times blacker than conventional black paint, to support the central idea.] 3. [Answers will vary. The summary should describe the central idea, as well as some of the supporting information. For example: Materials libraries are trying to inspire and wow visitors with the wide range of materials, some with highly unusual and interesting properties.]


The following Common Core ELA and math standards are covered in this unit as students work through the reading, class dialogue, and hands-on portion of the lessons.

ELA Standards

Applying ELA Connections to the Unit

Writing

W.8.1. Write arguments to support claims with clear reasons and relevant evidence.

• In Lesson 1, students write an analysis to the chemical reactions investigation, using their data to support their claims.

• In Lesson 2, students write a conclusion (argument) to summarize their findings in the polymer bounce experiment, analyzing whether or not the data (evidence) supported their hypothesis (claim).

W.8.2. Write informative/explanatory texts to examine a topic and convey ideas, concepts, and information through the selection, organization, and analysis of relevant content.

• In Lesson 2, students write out the polymer bounce experiment in their lab notebooks, including the question, research, hypothesis, experiment summary, materials, procedure, scientific diagram, data charts, graphs, and conclusion. They choose the relevant data points to use in their conclusion based on which data points best answer the question.

W.8.4. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.

• In Lesson 2, students produce clear and coherent writing as they use their lab notebooks to work through the polymer bounce experiment.

W.8.9. Draw evidence from literary or informational texts to support analysis, reflection, and research.

• In Lessons 1, 2, and 3, students use the nonfiction reading from their lab manuals to support their analysis, reflection, and research during the investigations and experiment.


Speaking and Listening

SL.8.1. Engage effectively in a range of collaborative discussions (one-on-one, in groups, and teacher-led) with diverse partners on grade 8 topics, texts, and issues, building on others' ideas and expressing their own clearly.

• In Lessons 1, 2, and 3, students engage in Socratic dialogue before beginning the experiment and investigations. Students apply what they have read in their lab manuals, as well as any personal experiences or observations, to the dialogue.

SL.8.4. Present claims and findings, emphasizing salient points in a focused, coherent manner with pertinent descriptions, facts, details, and examples; use appropriate eye contact, adequate volume, and clear pronunciation.

• In Lessons 1, 2, and 3, students analyze what they have learned in the lesson in the wrap-up portion of class, coming together as a class to discuss important takeaways from the hands-on portion of the lesson. Student teams compare results, using their data and background knowledge to support their claims and evaluate other teams’ claims.

Science and Technical Subjects

RST.6-8.1. Cite specific textual evidence to support analysis of science and technical texts.

• In Lessons 1, 2, and 3, students use the information they research in their lab manuals to support their understanding of how atoms and molecules combine in chemical reactions to form all of the matter in the world, and how scientists can use this knowledge to design new materials with a set of properties for specific functions.

•


RST.6-8.2. Determine the central ideas or conclusions of a text; provide an accurate summary of the text distinct from prior knowledge or opinions.

• In Lessons 1, 2, and 3, students read their lab manuals, determining the main ideas and conclusions of the text. They use this reading to inform and support the Socratic dialogue portion of the lesson.

RST.6-8.3. Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks.

• In Lesson 1, students follow a multistep procedure for combining two substances to determine if a chemical reaction took place.

• In Lesson 2, students follow a multistep procedure for testing how different amounts of borax affect polymer bounce height.

RST.6-8.9. Compare and contrast the information gained from experiments, simulations, video, or multimedia sources with that gained from reading a text on the same topic.

• In Lessons 1, 2, and 3, students apply what they read and discussed to the data they collected during the chemical reactions activity, the polymer bounce experiment, and the manufacturing processes activity, analyzing any differences between their results and what they read.

RST.6-8.10. By the end of grade 6, read and comprehend science/technical texts in the grades 6-8 text complexity band independently and proficiently.

• In Lessons 1, 2, and 3, students work on developing their understanding of science/technical texts by applying information from the lab manual to the chemical reactions activity, the polymer bounce experiment, and the manufacturing processes activity.


Unit 1: Appendix 3 Sample Concept Map

materials

pattern

endothermic

exothermic

chemical reaction

synthetic

looks at data for

explore

produces

scientist

experiment

data cause and

effect

can indicate

includes behaviors of

science system

polymer

chemical energy

matter

chemical change causes

atom

molecule

thermal energy

can be can be natural or

a large formed in

stored in bonds of

a form of

kinetic energy potential energy a form of

can be

change results in a

physical change

property have different

energy

forms of needed to change

made up of

element

made up of one kind of

structure function have

different

formed in

raw material

manufacturing

process

can be transformed in

follows

scale size can be

understood with


Unit 1: Appendix 4 Support for Differentiated Instruction

Core Expectation Assessment Strategies Possible Primary

Evidence 8. MS-PS1-1. Develop a model to describe that (a) atoms combine in a multitude of ways to produce pure substances which make up all of the living and nonliving things that we encounter, (b) atoms form molecules and compounds that range in size from two to thousands of atoms, and (c) mixtures are composed of different proportions of pure substances.

Low Entry Point • Recognize that substances are made

up of smaller parts that we cannot see.

• Identify the parts of individual atoms. • Describe how atoms combine to form

molecules and compounds. • Recognize that molecules can be

different sizes. At Grade-Level Entry Point • Describe relationships between atoms

within a molecule, and between molecules in a substance.

• Describe how the behavior of a substance is determined by its atomic/molecular structure.

• student diagram of an atom

• student diagram of a simple molecule (such as water, H20)

• “Chemical Reactions Investigation” sheet completed by student

• polymer bounce lab notebook entry completed by student

8. MS-PS-2. Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.

Low Entry Point • Organize substances according to

various physical properties (e.g., density, melting point, boiling point).

• Recognize that different substances can combine to form new substances with different properties.

At Grade-Level Entry Point • Compare physical and chemical

changes. • Use data to determine whether a

chemical reaction has occurred.


• polymer bounce lab notebook entry completed by student


Core Expectation Assessment Strategies Possible Primary Evidence

8. MS-PS1-4. Develop a model that describes and predicts changes in particle motion, relative spatial arrangement, temperature, and state of a pure substance when thermal energy is added or removed.

Low Entry Point • Recognize that temperature is

determined by the amount of thermal energy present.

• Identify that thermal energy changes the motion of a substance’s molecules, which causes a change in state.

At Grade-Level Entry Point • Describe how the addition or

removal of thermal energy changes the particle motion of a substance, which changes its temperature and state.

• student model demonstrating the changes in a substance’s particle motion when thermal energy is added or removed

• photos of student developing model of substance’s particle motion

8. MS-PS1-5. Use a model to explain that atoms are rearranged during a chemical reaction to form new substances with new properties. Explain that the atoms present in the reactants are all present in the products and thus the total number of atoms is conserved.

Low Entry Point • Recognize that all substances

are made up of atoms. • Identify that atoms can join in

various ways to form different substances.

At Grade-Level Entry Point • Use a model to show how mass

is conserved when two substances are combined in a chemical reaction.


• student diagram showing how mass is conserved in a chemical reaction


Core Expectation Assessment Strategies Possible Primary Evidence

8. MS-ETS2-4 (MA). Use informational text to illustrate that materials maintain their composition under various kinds of physical processing; however, some material properties may change if a process changes the particulate structure of a material.

Low Entry Point • Recognize that materials

undergo processing during manufacturing.

• Explain the difference between physical and chemical processing.

At Grade-Level Entry Point Describe how chemical

processing changes the particulate structure of a material.

• video of student explaining the difference between physical and chemical processing

MS-ETS2-5 (MA). Present information that illustrates how a product can be created using basic processes in manufacturing systems, including forming, separating, conditioning, assembling, finishing, quality control, and safety. Compare the advantages and disadvantages of human vs. computer control of these processes.

Low Entry Point • Recognize that a manufactured

product has been produced using a manufacturing process.

• Outline the steps that most manufacturing processes include.

At Grade-Level Entry Point • Explain why products need to

be produced using a manufacturing process.

• Describe how each step helps produce the finished product.

• student list of basic manufacturing processes

• video of student comparing the advantages and disadvantages of human vs. computer control of manufacturing processes


Unit 1: Appendix 5 Materials Chart

Lesson Quantity Notes Used Again

Unit Kit Consumable Goggles all 1 per student safety Hydrogen peroxide 3% 1 30 mL per team of 2 for chemical reactions activity Baking soda 1 3 g per team of 2 for chemical reactions activity Vinegar 1 30 mL per team of 2 for chemical reactions activity Potassium iodide (powder) 1 5 g per team of 2 for chemical reactions activity Foam cups 1 2 per team of 2 for reacting substances 30 mL graduated cups 1

2 2 per team of 2 2 per team of 2

for massing KI and baking soda for massing borax powder

Plastic spoons 1 2

2 per team of 2 1 per team of 2

for collecting KI and baking soda for collecting borax powder

Disposable gloves 1 2

1 pair/ student 1 pair/ student

safety

Plastic cups (small) 2 4 per team of 2 for mixing glue Craft sticks 2 2 per team of 2 for mixing glue/polymers Borax powder (sodium borate) 2 15 g per team of 2 for creating polymers School glue (polyvinyl acetate) 2 40g per team of 2 for creating polymers Plastic bags 2 1 per student for storing polymers Food coloring 2 2 colors shared for coloring polymers Keychain Manufacturing Process Cards (template set)

3 1 set per team of 6 (7 sheets per set)

for manufacturing process directions

Safety and quality control check sheets

3 8 per team of 6 for quality control check

Large paper clips 3 2 per team of 6 for quality control check Small paper clips 3 10 per team of 6 for plastic keychain hooks Plastic “discard” cups 3 1 per team of 6 for collecting plastic “waste” Plastic trays 3 1 per team of 6 for cool water bath Glue gun glue sticks 3 10 per team of 6 for creating plastic keychains Non-Consumable Digital scales all 1 per team of 2 for massing substances Graduated cups 1, 3 shared for measuring liquids (vinegar and

hydrogen peroxide)

Digital thermometers 1 1 per team of 2 for temperature data Graduated measuring containers

2, 3 teacher use water storage and transport

Measuring tape 2 1 per team of 2 for measuring polymer bounce Stopwatches 3 1 per team of 6 for timing manufacturing process Metal washers 3 10 per team of 6 for quality control testing Rubber molds 3 3 per team of 6 for molding plastic Teacher Tool Kit Masking tape 2 and 3 shared for taping Scissors 3 1 per team of 6 for trimming plastic keychains Glue guns 3 1-2 per team of 6 for creating plastic keychains Extension cords 3 teacher use for creating glue stations Power strips 3 teacher use for creating glue stations Permanent markers 3 1 per team/shared for coloring plastic keychains


Hand-outs Laboratory notebooks 2 1 per student for “Lab 1” Lab manuals 1, 2, 3 1 per student for “Chemical Reactions

Investigation” and “Manufacturing Process Investigation” sheets

Visuals Download Intro Lesson STEM Cycle Visual, Scientific Process Visual, Who is a Scientist Poster Lesson 1 Structure and Properties of Matter Visual, Atoms and Molecules Visual Lesson 2 Structure of Polymers Visual Lesson 3 Manufacturing Visual, Making Crayons Visual

Molecules to Materials Common Misconceptions

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Transcript of Molecules to Materials Common Misconceptions