| A | B |
|---|
| Democritus | atoms are indivisible particles |
| Dalton | All elements are made of atoms |
| Neils Bohr | atoms travel in energy levels around the atom |
| Ernest Rutherford | atoms are mostly empty space |
| Ernest Rutherford | atoms have a positive nucleus |
| J.J. Thomson | discovered the electron |
| J.J. Thomson | Electron 1/2000 size of H atom |
| Wave Theory | electron exist in a cloud around the nucleus |
| Democritus | atoms are small, hard particless |
| Democritus | "atomos" |
| Dalton | atom of different element are different |
| Dalton | atoms of the same element are the same |
| J.J. Thomson | cathode-ray experiment |
| Ernest Rutherford | Gold Foill Experiment |
