| A | B |
|---|
| Proton | Positive and found in center of atom |
| Neutron | Particle found in nucleus and has no charge |
| Electron | Particle with no mass and found outside the nucleus |
| Electron Cloud | Area outside nucleus where electrons are likely to be found |
| Atom | Smallest piece of matter that has all the properties of the element |
| Quarks | Make up protons and neutrons, 3 quarks in a proton, 3 in a neutron also |
| Atomic Mass Unit | 1.67x10^-24g |
| Atomic Number | Number of protons in a atom |
| Mass Number | Number of protons and neutrons in an atom |
| Isotopes | Same element (same number of protons) but different number of neutrons |
| Dalton | Proved atoms existed |
| Democritus | Created theory of atoms |
| Rutherford | Proton nucleus and free moving electrons around nucleus |
| Thompson | Introduced charged particles in atoms in chocolate chip cookie dough model |
| Bohr | Proton and neutron nucleus with electrons around nucleus in fixed orbits |
| Electron Cloud Model | Current model of atom with proton/neutron nucleus and electrons around nucleus in "electron cloud" |
