| A | B |
|---|
| electron | negative charge |
| proton | positive charge |
| neutron | neutral charge |
| nucleus | center of the atom |
| atom | smallest particle that retains the chemical identity of a substance |
| Rutherford | gold foil experiment |
| J.J. Thomson | plum pudding |
| Bohr | electrons orbit like the sun |
| ion | charged atom |
| isotope | same amount of protons, different neutrons |
| cation | positively charged ion |
| anion | negatively charged ion |
| mass number | addition of protons and neutrons |
| atomic number | determines protons and electrons |
| atomic mass | weighted average of the isotopes |
| orbital | area where electrons are found |
