| A | B |
|---|
| Democritus | Thought that matter could not be divided up an infinite number of times. |
| Aristotle | Thought that matter could be divided up an infinite number of times. |
| John Dalton | Proved that "atoms" really existed while studying weather |
| J.J. Thomson | Discovered the electron |
| Ernest Rutherford | Discovered the nucleus |
| Neils Bohr | Created models where the electrons have different energy levels. |
| James Chadwick | Discovered the neutron. |
| Experiment: Ran electricity through a gas and saw a glowing ray that could be bent by bringing magnets near it. | Conclusion: Atoms contain negatively charged particles that became known as electrons. |
| Experiment:Fired positively charged alpha particles at a thin sheet of gold foil and found that some of the particles were deflected or bounced back. | Conclusion: Atoms are mostly made of empty space with a small, massive center of positive charges. |
| Experiment: Weighed various kinds of atoms and found that most of them weighed about twice as much as expected. | Conclusion: The nucleus of an atom contains neutrons as well as protons. These neutrons have no charge. |
| Experiment:Seperated different types of air and combined different gas atoms to form compounds. | Conclusion:Matter is composed of small building blocks called "atoms" that cannot be broken down any further. |
| Greek Philosophers | Believed that understanding something could be settled by debating. |
| Modern Scientists | Believe understanding can be achieved by conducting experiments. |
| Another name for a hydrogen nucleus? | A Proton |
| Elements Greeks thought made up all matter | Earth, Wind, Fire, Water. |
| Came up with the plum pudding model | J.J. Thomson |
| Conducted the gold foil experiment | Ernest Rutherford |
| Model was a solid atom like a bb | John Dalton |
| Came up with the Planetaryl Model | Neils Bohr |
| Sending a current through a gas resulted in this | Cathod ray |
