Chapter 5

6. a number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction
7. a material that decreases the rate of a reaction
9. of Conservation of mass, the principle that the total amount of matter is neither created not destroyed during any chemical or physical change
12. that undergo the chemical change
14. a material that increases the rate of a reaction by lowering the activation energy
15. reaction, a reaction that absorbs energy
16. a reaction in which one emmental replaces another in a compound or when two events in different compounds trade places

1. a chemical reaction that breaks down compounds into simpler products
2. the amount of one material in a certain volume of another material
3. change/a change in matter that produces one or more new substances
4. a chemical reaction in which two or more simple substances combine to form a new (more complex) substance
5. the new substances that form
8. change/any change that alters the form or appearance of a substance but does no change it into another’s substance
10. energy, the minimum amount of energy needed to start a chemical reaction
11. a type of protein that speeds up a chemical reaction in a living thing (a biological catalyst that lowers the activation energy of reactions in cells
13. reaction, a reaction that releases energy (usually in the form of heat)