1

CHEMISTRY – CHAPTER 1Matter & Energy

2

Chapter 1 – Section 1

• Chemistry

3

What is Chemistry?

1. The natural sciences fall into two categories:

• Biological Sciences – the study of living things

ex. Botany, anatomy, zoology

4

• Physical Science – the study of matter and energy ex. geology, astronomy, earth science etc.

5

2. Chemistry is the study of the composition, structure and properties of substances and the changes they undergo.

6

Branches of Chemistry

1. Organic Chemistry – the study of substances that contain carbon.

2. Inorganic Chemistry – the study of all substances that do not contain carbon.

7

3. Physical Chemistry – the study of the inter-relationship between matter and energy

4. Biochemistry – the study of chemical processes that occur in living things.

8

5. Analytical Chemistry – the identification of substances.

6. Theoretical chemistry – the use of mathematics and computers to understand the principles behind observed chemical behavior and to design and predict the properties of new compounds.

9

Types of ResearchChemists are usually involved in 3 basic types of research.

1. Basic Research - is carried out for the sake of increasing knowledge, such as how and why a specific reaction occurs.

2. Applied Research – is generally carried out to solve a problem.

3. Technological Development – typically involves the production and use of products that improve our quality of life.

In many cases, the three types of researchoverlap.

10

What is a Chemical?

1. A chemical is any substance used in or produced by a chemical process.

2. Every material and substance is made of chemicals. Anything can be a chemical.

3. Unfortunately, the word chemical has become associated with undesirable circumstances-pollution, cancer, poisonings, etc.

11

4. A substance that is a chemical is not by definition, harmful. Nor can anything be “free of chemicals”

12

The Scientific Method

The scientific method is a logical approach to problem solving.

The most basic steps are as follows:

1. Make observations

2. Ask questions

4. Testing

5. Form a theory

7. Publish Results

6. Form a conclusion

3. Form a hypothesis

13

Experimentation

1. When setting up an experiment there should be a control group and an experimental group.

2. The control group is used for comparison.

3. The experimental group has one variable that is changed. This variable is

called the independent variable.

4. The dependent variable is the result of the independent variable.

14

Sue is convinced African violets grow better under fluorescent lights. To test this hypothesis, she purchases 50 plants. She then numbers the pots 1-50 and measures the height of each plant. Then, she separates the plants into two groups of 25 each.Each plant is potted with the same soil and receives the same amount of water and fertilizer. Group 1-25 is placed in sunlight for 7 hours per day, and group 26-50 is placed under fluorescent lights for 7 hours per day.

a. Identify the control group.b. Identify the experimental groupc. Identify the independent variabled. Identify the dependent variablee. Identify the constants.

15

DATA

1. Data is information gotten from observations.

2. There are two types of data.

• Quantitative data – numerical data

• Qualitative data – non-numerical data

Ex. Length, mass, density etc.

Ex. Color, smell, shape, texture, etc.

16

Hypothesis vs. Theory

1. A hypothesis is a testable statement. It serves as a basis for making predictions

2. A theory is a broad generalization that explains a body of facts or phenomena.

• A theory is successful if it can predict the results of many new experiments.

• Models can be used to explain theories. Models are may be visual, verbal or mathematical. It is a physical object used to explain how phenomena occur.

• A theory can not be proven nor disproved. Ex. The origin of the universe

17

A Law

1. A law is a broad generalization the is always true under normal conditions

The law of gravity

18

Chapter 1 – Section 2

• Matter

19

Matter and Its Properties

1. Matter is anything that has mass and takes up space.

Give examples of matter in the picture above

20

Matter and Its Properties

Matter is anything that has mass and takes up space.

Three properties of matter:

a. Inertia – a resistance to change in motion. Objects at rest will remain at rest unless a force acts upon them.

21

b. Mass – is the quantity of matter in an object.

c. Weight – is the pull of gravity on an object

22

Weight changes with the changes in gravity but mass does not.

The law of conservation of mass states that matter cannot be created or destroyed in an ordinary chemical or physical change.

23

Energy – is the ability to cause change or do work.

There are several types of energy:• Chemical

• Electrical

• Mechanical

• Sound

The law of conservation of energy states that energy cannot be createdor destroyed it is simply converted from one form to another.

24

Energy is never lost it is simply converted into a form that cannotBe recaptured for effective use. Usually heat energy.

All energy can be classified into two categories:

25

Kinetic energy - energy of an object in motion

26

Potential energy – stored energy, energy at rest or due to position.

27

The Building Blocks of Matter

An atom is the smallest unit of an element

28

2. An element is a pure substance made of only one kind of atom.

3. A compound is a substance that is made from the atoms of two or more elements that are chemically bonded.

29

4. Two or more of the same type of atoms form elements and several different types of atoms form compounds.

30

Properties and Changes in Matter

1. A property is a characteristic that defines or identifies a group or substance.

2. Properties are either:

• Extensive properties – depend on the quantity of matter present. (mass, volume, length, and amount)• Intensive properties – do not depend on the amount of matter

present ( melting point, boiling point, density, conductivity

3. A physical property is a characteristic that can be observed or measured without changing the identity of the substance. (ex. Melting point and boiling point)

4. A physical change involves a change in which the identity of a substance is not

altered.

31

5. Phase changes (changes in states) are always a physical change.

Solid

Liquid

Gas

melting

evaporationcondensation

freezing

sublimationdeposition

32

6. A change of state is a physical change from one state of matter to another.

Solid

Gas

33

7. The four states of matter.

• Solids have definite shape and volume.

• Liquids have definite volume but no definite shape.

• Gases have not definite shape or volume.

Solid Liquid Gas

34

• Plasma is a high temperature physical state of matter in which atoms lose their electrons, therefore, it contains charged particles.

35

8. A chemical property relates to a substance’s ability to undergo changes that that transform it into different substances.

9. A chemical change or chemical reaction occurs when one or more substances are converted into a different substance.

Ex. Flammability, reactivity, or combustibility

10. The substances that react are called the reactants. The substances that are produced are called the products.

Carbon + Oxygen → carbon dioxide

reactants products

36

11. The three indications of a chemical reaction

• The production of heat/light

• The production of a gas

• The production of a precipitate

37

12. All physical and chemical changes involve a change of energy. These changes can be:

• Endothermic – energy is absorbed.

• Exothermic – energy is released.

13. In the sciences a positive number (+) means endothermic and a negative number (-) means exothermic. Endothermic reactions feel cold to the touch and exothermic warm or hot.

38

Classification of Matter1. A mixture is a blend of two or more kinds of matter, each retaining its own identity and properties.

39

2. A homogenous mixture is the same throughout. A homogenous mixture is called a solution.

•

40

3. A heterogeneous mixture is not uniform throughout

41

4. A pure substance has a fixed composition and is a compound or element

42

Chapter 1 – Section 3

• Elements

43

Elements and the Periodic table

1. The periodic table is a listing of all elements by increasing atomic number.

44

2. The vertical columns are called groups. There are 18 groups.

3. The horizontal rows are called periods. There are 7 periods

45

4. The periodic table can be separated into metals, nonmetals, and metalloids.

46

5. Metals are shiny, malleable, ductile, and good conductors of heat and electricity.

6. Nonmetals are not shiny, malleable, ductile, or good conductors of heat and electricity.

carbonsulfur phosphorus iodine