1 CHEMISTRY – CHAPTER 1 Matter & Energy. Objective #3 Objective: Understand energy and matter. –Before: Introduction to energy and matter –During: Discuss.

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CHEMISTRY – CHAPTER 1Matter & Energy

Objective #3

• Objective: Understand energy and matter.– Before: Introduction to energy and matter– During: Discuss energy and its relationship to

matter– After: Review energy and its relationship to

matter

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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.

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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:

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Kinetic energy - energy of an object in motion

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

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The Building Blocks of Matter

An atom is the smallest unit of an element

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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.

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

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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.

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

Solid

Liquid

Gas

melting

evaporationcondensation

freezing

sublimationdeposition

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

Solid

Gas

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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

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

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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

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11. The three indications of a chemical reaction

• The production of heat/light

• The production of a gas

• The production of a precipitate

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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.

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

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

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3. A heterogeneous mixture is not uniform throughout

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

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Chapter 1 – Section 3

• Elements

Objective #4

• Objective: Understand elements and the periodic table– Before: Introduction to the elements and the

periodic table– During: Discuss the elements and the

periodic table– After: Review the elements and the periodic

table

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Elements and the Periodic table

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

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

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

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

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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