Chapter 5

4. occurs when compounds break down into similar products
7. biological catalysts that help reactions occur at body temperature
9. energy the minimum amount of energy required to start a chemical equation
10. Change a change in matter that produces one or more new substances
11. the new substances that form
13. reaction more energy is required to break bonds of the reactants than is released by the formation of the products.
14. reaction a way to show a chemical reaction, using symbols instead of words
17. substances that undergo the chemical changes

1. increases the reaction rate by lowering the activation energy needed
2. reaction the energy released as products form is greater than the energy required to break bonds of the reactants
3. when one element replaces another in a compound or if 2 elements in different compounds trade places
5. the amount of a substance in a given volume
6. when 2 or more elements or compounds combine to make a more complex substance
8. a material used to decrease the rate of a chemical reaction
11. Change any change that alters the form or appearance of a substance but doesn’t change into another substance
12. a number placed in front of a chemical formula in an equation
15. a solid that forms from liquids during a chemical reaction
16. of Conservation of Mass matter is not created or destroyed