Chapter 7

4. A substance that affects the rate of a chemical reaction without being used up in the reaction (215)
5. The mass of one mole of a substance (196)
9. The energy stored in chemical bonds (206)
10. A system releases energy to its surroundings
12. Numbers that appear before a formula in a chemical equation (194)
14. A chemical reaction in which the reactants and products are expressed as formulas (193)
15. A system absorbs energy from its surroundings
16. When a compound breaks down into two or more simpler substances (200)
17. Electrons are transferred from one reactant to another (204)
18. Two or more substances react to form a single substance (200)
19. A counting unit to measure amounts of substance since chemical reactions involve large numbers of small particles (195)

1. New substances formed as a result of a chemical reaction (192)
2. Two compounds exchange positive ions and form two new compounds (203)
3. A substance reacts rapidly with oxygen often producing heat and light (204)
6. One element takes the place of another element in a compound (202)
7. A chemical reaction in which the conversion of reactants into products and the conversion of products into reactants happens at the same time
8. A substance that undergoes change in a chemical reaction (192)
11. A state in which the forward and reverse paths of a physical or chemical change take place at the same rate (216)
13. The rate at which reactants change into products over time (212)