chapter 2

4. a reaction that absorbs energy in the form of heat
7. a solid that forms from a solution during a chemical reaction
8. a material that decreases the rate of reaction
9. anything that has mas and occupies space
11. a short easy way to show a chemical reaction
14. a substance that enters into a chemical reaction
15. a characteristic of a substance that can be observed without changing the substance into another substance
16. a system in which matter can enter from or escape to the surroundings
17. a substance formed as a result of chemical reaction
19. a biological catalyst that lowers the activation energy of reactions in cells
22. a change that alters the form or appearance of a material but does not make the material into another substance
23. the study of matter and how matter changes

1. a rapid reaction between oxygen and fuel that results in fire
2. a reaction that releases energy in the form of heat
3. the minimum amount of energy needed to get a chemical reaction started
5. a characteristic of a substance that describes the ability to change into different substances
6. the principal stating that matter is not created or destroyed during a chemical reaction
10. a reaction in which one element replaces another in a compound or when two elements in different compounds trade places
12. the amount of one material in a certain volume of another material
13. a material that increases the rate of reaction by lowering the activation energy
18. a system in which no matter is allowed to enter or leave
20. a material that releases energy when it burns
21. a number infront of a chemical formula in an equation