Unit 2: Chemical InteractionsChapter 6: Chemical Reactions

Big Idea: Chemical reactions are processes in which atoms are

rearranged into different combinations of molecules

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4 Sections

1. Observing Chemical Change

2. Describing Chemical Reactions

3. Controlling Chemical Reactions

4. Fire & Fire Safety

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Sec 1: Observing Chemical Change

KEY CONCEPTS• Changes in matter can be described in terms of

physical changes & chemical changes• Chemical changes occur when bonds break &

new bonds form• Chemical reactions involve changes in properties

& changes in energy that you can observe

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Sec 1: Key Terms

• Matter• Chemistry• Physical property• Chemical property• Physical change• Chemical change

• Reactant• Product• Precipitate• Endothermic reaction• Exothermic reaction

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Sec 2: Describing Chemical Reactions

KEY CONCEPTS

• Chemical equations use chemical formulas & other symbols instead of words to summarize a reaction

• In chemical reactions, the number of atoms stays the same no matter how they are arranged, so their total mass stays the same

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Sec 2: Describing Chemical Reactions (cont’d)

• To describe a reaction accurately, a chemical equation must show the same number of each type of atom on both sides of the equation

• 3 general types of chemical reactions are synthesis, decomposition & replacement

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Sec 2: Key Terms

• Chemical equation• Conservation of

matter• Open system• Closed system

• Coefficient• Synthesis• Decomposition• Replacement

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Sec 3: Controlling Chemical Reactions

KEY CONCEPTS

• All chemical reactions require a certain amount of activation energy to get started

• Factors that affect rates of reaction include surface area, temperature, concentration & the presence of catalysts or inhibitors

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Sec 3: Key Terms

• Activation energy• Concentration• Catalyst• Enzyme• Inhibitor

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Sec 4: Fire & Fire Safety

KEY CONCEPTS• The following 3 things are necessary to

start & maintain a fire: 1) fuel2) oxygen3) heat

• If you know how to prevent fires in your home & what to do if a fire starts, you are better prepared to take action

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Sec 4: Key Terms

• Combustion• Fuel