| A | B |
|---|
| Democritus | 440 BC |
| Thomson | 1897 |
| Bohr | 1913 |
| Rutherford | 1911 |
| Dalton | 1803 |
| Schrodinger and Heisenberg | 20th Century |
| There are small negatively charged particles inside an atom. | Thomson |
| There is a small, dense, positively charged nucleus. | Rutherford |
| Most of an atom's mass is in the nucleus. | Rutherford |
| Electrons jump between levels from path to path. | Bohr |
| He conducted the cathode-ray tube experiment. | Thomson |
| Atoms of different elements are different. | Dalton |
| Atoms contain mostly empty space. | Rutherford |
| Atoms are small, hard particles. | Democritus |
| He conducted experiments in combining elements. | Dalton |
| Atoms are "uncuttable". | Democritus |
| Electron paths cannot be predicted. | 20th Century |
| Electrons travel in definite paths. | Bohr |
| Electrons move in empty space in the atom. | Rutherford |
| His theory of atomic structure became the "plum-pudding" model | Thomson |
| Electrons are found in electron clouds, not paths. | 20th Century |
| Atoms of the same element are exactly alike. | Dalton |
| Atoms constantly move. | Democritus |
| All substances are made from atoms. | Dalton |
| He conducted the gold foil experiment. | Rutherford |
| Elements combine in specific proportions. | Dalton |
