| A | B |
|---|
| atom | smallest basic unit of matter |
| element | substance made of only one type of atom that cannot be broken down by chemical means |
| compound | substance made of atoms of different elements that are bonded together in a particular ratio |
| ion | atom that has gained or lost one of more electrons |
| ionic bond | chemical bond formed through the electrical force between oppositely charged ions |
| covalent bond | chemical bond formed when two atoms share one or more pairs of electrons |
| molecule | two or more atoms held together by covalent bonds; not necessarily a compound |
