Claire Y

1. the smallest unit of an element
4. a link between atoms in molecules or compounds
5. the transfer of thermal energy
6. the ability to do work or cause change
7. the substances that are formed during a chemical reaction; in a chemical reaction the arrows point toward the product
8. a science that deals with the composition, structure, and properties of substances
13. a chemical reaction that absorbs heat energy
14. it takes up space and has mass
15. a substance that can be added to a reaction to increase the reaction rate without getting consumed in the process

2. a combination of substances that can be physically separated from one another
3. two or one atoms joined together
6. chemical reaction that gives off heat energy
9. a measure of the average kinetic energy of the atoms in a system, used to express thermal energy in degrees
10. the substances present before a chemical reaction occurs
11. the amount of space that an object occupies
12. an action taken in response to something
15. the ability of molecules of the same substance to stick together