Chapter 5

3. reaction the energy released as products form is greater than the energy required to break bonds of the reactants
6. of Conservation of Mass matter is not created or destroyed
8. Change any change that alters the form or appearance of a substance but doesn’t change into another substance
11. when one element replaces another in a compound or if 2 elements in different compounds trade places
13. energy the minimum amount of energy required to start a chemical equation
14. reaction a way to show a chemical reaction, using symbols instead of words
15. biological catalysts that help reactions occur at body temperature
16. a material used to decrease the rate of a chemical reaction
17. the new substances that form
18. a solid that forms from liquids during a chemical reaction

1. increases the reaction rate by lowering the activation energy needed
2. substances that undergo the chemical changes
4. reaction more energy is required to break bonds of the reactants than is released by the formation of the products.
5. Change a change in matter that produces one or more new substances
7. when 2 or more elements or compounds combine to make a more complex substance
9. the amount of a substance in a given volume
10. occurs when compounds break down into similar products
12. a number placed in front of a chemical formula in an equation