| A positively charged ion is called a ____. |
atom |
| A group of atoms held together by covalent bonds is a ____. |
catalyst |
| Any atom or molecule that has a charge is an ____. |
cation |
| A ____ is a subatomic particle with no electric charge. |
compound |
| A ____ contains atoms of at least two different elements. |
ion |
| A ____ increases the rate of a chemical reaction. |
molecule |
| A ____ is subatomic particle with a positive charge. |
neutron |
| The basic unit of an element is an ____. |
proton |
