Chemistry

3. the study of matter
4. the substances you have a the beginning
6. the amount of a substance in a given volume
7. when on element replaces another in a compound
10. a reaction which energy is absorbed
11. when two or more elements combined to make more complex substances
13. any change the alters the appearance of a substance
15. a change in matter that produces one or more substances
17. any thing that has mass and takes up space
18. new substance after the reaction
20. matter is not allowed to enter or leave
22. matter can enter from or escape to the surroundings
23. a reaction between oxygen and fuel
24. breaks down compounds into simpler products
25. a characteristic of a substance that can be observed without changing the substance into another substance
26. biological catalysts

1. a solid that forms from solution during a chemical reaction
2. a reaction that releases energy in the form of heat
5. minimum amount of energy needed to start a chemical reaction
8. a number placed in front of a chemical formula
9. used to decrease the rate of reaction
12. during a chemical reaction matter is not created of destroyed
14. a way to show chemical reactions using symbols
16. increases the rate of reaction by lowering the activation energy
19. a characteristic of a substance that describes its ability to change into other substances
21. releases energy when it buns