| A | B |
|---|
| Atom | The smallest particle into which an element can be divided and still be the same substance |
| theory | a unifing explination for a broad range of hypotheses and observations, supported by testing |
| Electrons | Negatively charged particles found in all atoms |
| Protons | positively charged particles found in the nucleus of an atom |
| Neutrons | particles found in the nucleus that have no charge |
| Nucleus | a tiny, extremely dense region found in the center of the atom that is positively charged |
| Atomic Number | The number of protons in the nucleus of the atom |
| atomic mass | the sum of the protons and neutrons in the nucleus |
