| A | B |
|---|
| Atomic Number | the number of protons and electrons in an atom |
| Atomic Mass | the number of protons and neutrons in the nucleus |
| Protons | positive charge, located in the nucleus |
| Neutrons | no charge, located in the nucleus |
| Electrons | negative charge; orbit around the nucleus |
| Nucleus | made up of protons and neutrons, where most of the mass is located in an atom |
| Atom | the smallest unit of matter |
| Matter | Anything that has mass and takes up space (volume) |
