Democitus model
Democritus was the inventor of the atomic theory. In 400 B.C he said that all things where made of little particles that could not be divided or destroyed. He called these particles átomos. His idea was not excepted or studied till 2000 years later.
Thomson Atomic Model
J.J. Thomson believed that they atom was just negatively charged electrons with a positively charged shell. Used cathode rays to show movement of atom. He determined this was caused by little electrically charged particles called electrons.
Rutherford Atomic Model
Ernest Rutherford decided to put Thomson's Model to the test and set up an experiment using golf foil and a cathode ray and it showed some of the rays reflected back. The results showed there was a strong center piece to the atom. He revised Thomson's model and came up with a atom that has a strong center nucleus that is positively charged. He used rays that bounced of the nucleus amd that showed a strong central center.
The electron cloud
Erwin shroud her and Louis de brogile discovered the electron cloud in 1926. This Model said that many different electrons with different charges floated freely around a nucleus made up of protons and neutrons. Using a series of different math equations he determined the probability of an atom being in a certain place.
