| A | B |
|---|
| valence shell | the outermost shell of the atom |
| octet rule | Atoms want to have 8 electrons in their outer shell |
| Endothermic | A reaction that takes in energy |
| Activation Energy | Energy needed to start a chemical reaction |
| Exothermic | A reaction that releases energy |
| Ion | Atoms with either a positive or negative electrical charge |
| Valence electron | The electrons found in the outermost shell of an atom |
| Covalent Bond | The type of bond where electrons are shared between the atoms |
| Ionic Bond | The type of bond where atoms give electrons to other atoms |
