chemical interactions

2. the substances you have at the beginning.
5. a reaction that releases energy in the form of heat.
6. use chemical formulas and other symbols instead of words to summarize reaction.
9. a material that used to work by preventing reactants from coming together.
10. the study of matter and how matter changes
14. the amount of a substance in a given volume
15. when two or more elements or compounds combine to make more complex substances.
19. a solid that forms from solution during a chemical reaction
22. a characteristic of a substance that can be observed without changing the substance into another substance.
23. the cells in your body contain biological catalysts.
24. matter can enter from or escape to surroundings.
25. can be described in the terms of two kinds of properties, physical and chemical.
26. when the reaction is complete, you have new substances.

1. the minimum amount of energy needed to start a chemical reaction.
3. during a chemical reaction, matter is not created or destroyed.
4. any change that alters the form or appearance of a substance but that does not make the substance into another substance.
7. a reaction in which energy is absorbed
8. when two elements in different compounds trade places.
11. the result of fire
12. matter is not allowed to enter or leave.
13. a characteristic of a substance that describes its ability to change into other substances.
16. a material that increases the rate of a reaction by lowering the activation energy.
17. a number placed in front of a chemical formula in am equation
18. breaks down compounds into simpler products.
20. A change in matter that produces one or more new substances
21. a material that releases energy when it burns