| A ____ contains atoms of at least two different elements. |
catalyst |
| A ____ is a subatomic particle with no electric charge. |
compound |
| An ____ consists of only one type of atom. |
electron |
| A proton and a neutron have about the same ____ (1 amu). |
element |
| Any atom or molecule that has a charge is an ____. |
ion |
| Diamond is the hardest naturally occurring ____ on Earth. |
mass |
| An ____ is subatomic particle with a negative charge. |
mineral |
| A ____ increases the rate of a chemical reaction. |
neutron |
