Hstp ch04

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Chapter Presentation

Transparencies

Image and Math Focus Bank

Bellringers

Standardized Test Prep

Visual Concepts

Resources



Elements, Compounds, and Mixtures

Table of Contents

Section 1 Elements

Section 2 Compounds

Section 3 Mixtures

Chapter 4



Section 1 Elements

Bellringer

Refer to Figure 4 in your book for help answering the following questions:

What do gold, iron, and aluminum have in common?

What do oxygen, neon, and sulfur have in common?

How is silicon different from aluminum or oxygen?

Chapter 4




Section 1 Elements

Objectives

• Describe pure substances.

• Describe the characteristics of elements, and give examples.

• Explain how elements can be identified.

• Classify elements according to their properties.

Chapter 4



Section 1 Elements

Elements, the Simplest Substances

• An element is a pure substance that cannot be separated into simpler substances by physical or chemical means.

• Only One Type of Particle A substance in which there is only one type of particle is a pure substance. Elements are made of particles called atoms.

Chapter 4



Section 1 Elements

Properties of Elements

• Each element can be identified by its unique set of properties. An element may share a property with another element, but other properties can help you tell the elements apart.

• Identifying Elements by Their Properties Elements can be identified by using their physical properties and their chemical properties.

Chapter 4



Section 1 Elements

Classifying Elements by Their Properties

• Categories of Elements Three major categories are:

• Metals are shiny, and they conduct heat energy and electric current.

• Nonmetals conduct heat and electricity poorly.

• Metalloids have properties of both metals and nonmetals.

Chapter 4



Section 1 Elements

Classifying Elements by Their Properties, continued

• Categories Are Similar By knowing the category to which an unfamiliar element belongs, you can predict some of its properties.

• The next slide show examples and properties of metals, nonmetals, and metalloids.

Chapter 4



Section 1 ElementsChapter 4



Section 2 Compounds

Bellringer

The word compound refers to something that consists of two or more parts. How might you make a compound using elements? What are some compounds that you know?

Write your answer in your science journal.

Chapter 4



Section 2 Compounds

Objectives

• Explain how elements make up compounds.

• Describe the properties of compounds.

• Explain how a compound can be broken down into its elements.

• Give examples of common compounds.

Chapter 4



Section 2 Compounds

Compounds: Made of Elements

• A compound is a pure substance composed of two or more elements that are chemically combined. Elements combine by reacting with one another.

• A particle of a compound is a called a molecule. Molecules of compounds are formed when atoms of two or more elements join together.

Chapter 4



Section 2 Compounds

Compounds: Made of Elements

• The Ratio of Elements in a Compound Elements join in a specific ratio according to their masses to form a compound.

• For example, every sample of water has a 1:8 mass ratio of hydrogen and oxygen.

Chapter 4



Section 2 Compounds

Properties of Compounds

• Each compound can be identified by its physical and chemical properties.

• Properties: Compounds Versus Elements A compound has properties that differ from those of the elements that form it.

Chapter 4



Section 2 Compounds

Breaking Down Compounds

• Compounds can be broken down into their elements or into simpler compounds by chemical changes.

• Methods of Breaking Down Compounds Sometimes, energy is needed for a chemical change to happen. Two ways to add energy are to apply heat and to apply an electric current.

Chapter 4



Section 2 Compounds

Compounds in Your World

• Compounds in Nature Some compounds found in nature are proteins, carbon dioxide, and carbohydrates.

• Compounds in Industry Some compounds must be broken down for use in industry. Other compounds, are made in industry for use as medicines, food preservatives, and synthetic fabrics.

Chapter 4



Section 3 Mixtures

Bellringer

Chapter 4



Section 3 Mixtures

Objectives

• Describe three properties of mixtures.

• Describe four methods of separating the parts of a mixture.

• Analyze a solution in terms of its solute and solvent.

Chapter 4



Section 3 Mixtures

Objectives, continued

• Explain how concentration affects a solution.

• Describe the particles in a suspension.

• Explain how a colloid differs from a solution and a suspension.

Chapter 4



Section 3 Mixtures

Properties of Mixtures

• A mixture is a combination of two or more substances that are not chemically combined.

• No Chemical Changes in a Mixture

Chapter 4



Section 3 Mixtures

Properties of Mixtures, continued

• Separating Mixtures Through Physical Methods

• The next slide shows some common ways to separate mixtures by using physical changes.

Chapter 4



Section 3 Mixtures

Properties of Mixtures, continued

• The Ratio of Components in a Mixture The components of a mixture do not need to be mixed in a definite ratio.

• For example, granite is a mixture of three minerals. Different ratios of the minerals give granite different colors, but the mixture is always called granite.

Chapter 4



Section 3 Mixtures

Solutions

• A solution is a mixture that appears to be a single substance. The process in which particles of substances separate and spread evenly throughout a mixture is known as dissolving.

• In a solution, the solute is the substance that is dissolved. The solvent is the substance in which the solute is dissolved.

Chapter 4



Magnetic attraction



Filtration



Distillation



Evaporation



Section 3 Mixtures

Solutions, continued

• Examples of Solutions Liquid solutions include soft drinks, gasoline, and tap water. Solutions may also be gases, such as air.

• Solutions may also be solids, such as steel. Alloys are solid solutions of metals or nonmetals dissolved in metals.

Chapter 4



Section 3 Mixtures

Solutes, Solvents, and Solutions

Chapter 4

Click below to watch the Visual Concept.

You may stop the video at any time by pressing the Esc key.

Visual Concept



Section 3 Mixtures

Solutions, continued

• Particles in Solutions The particles in solutions are so small that they never settle out. They also cannot be removed by filtering.

• The particles in solutions are so small that they don’t even scatter light.

Chapter 4



Section 3 Mixtures

Concentrations of Solutions

• A measure of the amount of solute dissolved in a solvent is concentration. • Concentrated or Dilute? Solutions can be described as being concentrated or dilute. But these two terms do not tell you the amount of solute that is dissolved.

• The next slide shows how to calculate concentration.

Chapter 4



Section 3 MixturesChapter 4



Section 3 Mixtures

Concentrations of Solutions, continued

• Solubility is the ability of a solute to dissolve in a solvent at a certain temperature.

• The solubility of most solids in water increases with temperature. The graph on the next slide shows this relationship.

Chapter 4



Section 3 Mixtures

Concentrations of Solutions, continued

• Dissolving Gases in Liquids Gases become less soluble in liquids as the temperature is raised.

• Dissolving Solids Faster in Liquids Three ways to make a solute dissolve faster are mixing the solution, heating the solution, and crushing the solute into smaller particles.

Chapter 4



Section 3 Mixtures

Suspensions

• A suspension is a mixture in which particles of a material are dispersed throughout a liquid or a gas but are large enough that they settle out.

• The particles in a suspension are large enough to scatter or block light. A suspension can be separated by passing it through a filter.

Chapter 4



Section 3 Mixtures

Colloids

• A colloid is a mixture in which the particles are dispersed throughout but are not heavy enough to settle out.

• Particles in a colloid are large enough to scatter light. A colloid cannot be separated by passing it through a filter.

Chapter 4



Elements, Compounds, and Mixtures

Use the terms below to complete the concept map on the next slide.

Chapter 4

Concept Map

mixturecolloidfilterelement

suspensionsolutioncompound



Elements, Compounds, and MixturesChapter 4



End of Chapter 4 Show



Reading

Read each of the passages. Then, answer the questions that follow each passage.

Chapter 4 Standardized Test Preparation



Passage 1 In 1912, the Titanic was the largest ship ever to set sail. This majestic ship was considered to be unsinkable. Yet, on April 15, 1912, the Titanic hit a large iceberg. The resulting damage caused the Titanic to sink, killing 1,500 of its passengers and crew.

How could an iceberg destroy the 2.5 cm thick steel plates that made up the Titanic’s hull?

Continued on the next slide




Passage 1, continued Analysis of a recovered piece of steel showed that the steel contained large amounts of sulfur. Sulfur is a normal component of steel. However, the recovered piece has much more sulfur than today’s steel does. The excess sulfur may have made the steel brittle, much like glass. Scientists suspect that this brittle steel may have cracked on impact with the iceberg, allowing water to enter the hull.




1. In this passage, what does the word brittle mean?

A likely to break or crack

B very strong

C clear and easily seen through

D lightweight




2. What is the main idea of the second paragraph of this passage?

F The Titanic’s hull was 2.5 cm thick.

G The steel in the Titanic’s hull may have been brittle.

H The large amount of sulfur in the Titanic’s hull may be responsible for the hull’s cracking.

I Scientists were able to recover a piece of steel from the Titanic’s hull.




3. What was the Titanic thought to be in 1912?

A the fastest ship afloat

B the smallest ship to set sail

C a ship not capable of being sunk

D the most luxurious ship to set sail




Passage 2 Perfume making is an ancient art. It was practiced by the ancient Egyptians, who rubbed their bodies with a substance made by soaking fragrant woods and resins in water and oil. Ancient Israelites also practiced the art of perfume making. This art was also known to the early Chinese, Arabs, Greeks, and Romans.

Continued on the next slide




Passage 2, continued Over time, perfume making has developed into a fine

art. A good perfume may contain more than 100 ingredients. The most familiar ingredients come from fragrant plants, such as sandalwood or roses. These plants get their pleasant odor from essential oils, which are stored in tiny, baglike parts called sacs. The parts of plants that are used for perfumes include the flowers, roots, and leaves. Other perfume ingredients come from animals and from human-made chemicals.





1. How did ancient Egyptians make perfume?

A by using 100 different ingredients

B by soaking woods and resins in water and oil

C by using plants or flowers

D by making tiny, baglike parts called sacs




2. What is the main idea of the second paragraph?

F Perfume making hasn’t changed since ancient Egypt.

G The ancient art of perfume making has been replaced by simple science.

H Perfume making is a complex procedure involving many ingredients.

I Natural ingredients are no longer used in perfume.




3. How are good perfumes made?

A from plant oils only

B by combining one or two ingredients

C according to early Chinese formulas

D by blending as many as 100 ingredients




Interpreting Graphics

The graph below was constructed from data collected during a laboratory investigation. Use the graph below to answer the questions that follow.




1. Which of the following values is the amount of sodium nitrate that can dissolve in 100 mL of water at 40°C?

A 0 g

B 40 g

C 80 g

D 100 g




2. How many grams of sodium chloride can dissolve in 100 mL of water at 60°C?

F 40 g

G 80 g

H 125 g

I 160 g




3. At what temperature will 80 g of potassium bromide completely dissolve in 100 mL of water?

A approximately 20°C

B approximately 42°C

C approximately 88°C

D approximately 100°C




4. At 20°C, which solid is the most soluble?

F sodium chloride

G sodium chlorate

H potassium bromide

I sodium nitrate




Math

Read each question, and choose the best answer.




1. What is the perimeter of the rectangle shown below?

A 12 cm

B 18 cm

C 36 cm

D 72 cm


12 cm

6 cm



2. If the length of all the sides of the rectangle shown below were doubled, what would be the area of the larger rectangle?

F 36 cm2

G 72 cm2

H 144 cm2

I 288 cm2


12 cm

6 cm


ResourcesChapter menuChapter menu

2. If the length of all the sides of the rectangle shown below were doubled, what would be the area of the larger rectangle?

F 36 cm2

G 72 cm2

H 144 cm2

I 288 cm2


12 cm

6 cm



3. One way to calculate the concentration of a solution is to divide the grams of solute by the milliliters of solvent. What is the concentration of a solution that is made by dissolving 65 g of sugar (the solute) in 500 mL of water (the solvent)?

A 0.13 g•mL

B 0.13 g/mL

C 7.7 g•mL

D 7.7 g/mL




4. If 16/n 1/2, what is the value of n?

F 2

G 8

H 16

I 32




Section 1 ElementsChapter 4

Hstp ch04

Technology

Transcript of Hstp ch04