Chemistry

2. a reaction in which one element is substituted for another element
4. a negatively charged ion
5. any substance composed of identical molecules consisting of atoms of two or more chemical elements
7. a reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat
11. bonded atoms have a lower total energy than that of widely separated atoms
12. chemical reaction in which one reactant breaks down into two or more products
14. occur when parts of two ionic compounds are exchanged, making two new compounds

1. nitrogen, oxygen, fluorine, chlorine, bromine, iodine, and hydrogen
3. an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
6. breaking of existing bonds and the formation of new ones
8. subatomic particle that together with protons and neutrons form an atom's nucleus
9. A number placed in front of a formula to balance a chemical equation.
10. atom or group of atoms that bears a positive electric charge.
13. has either a positive charge (cation) or negative charge (anion)