History of the Atom by Jamal Smiles and Ron Wicks

Aristotle (368 b.c)

500

Aristotle didnt agree with Democritus. Aristotle beleived everything was made up of air, fire, water, and earth.
His method for finding this was his beleif that you can find things out by thinking about it.

Democritus (460 b.c)

500

He thought that if you kept breaking something down, you would eventually get to spot where it cant be broken anymore. He didnt use a method or crate a model, but his atom may be thought as a very small dot.

Dalton

Mar 7, 1805

He discovered elements consisted of tiny particles called atoms. He thought that the reason all the elements are pure is because all the atoms are the same. His method used was the law of simple proportions. He thought all teh particles were the same size.

Thomson

Mar 7, 1897

He discovered the electron. He found that they were very small. This made Dalton's model was wrong, To find this, Thomson used a cathode ray tube. His maodel he made was named the plum pudding model. The electrons were stuck in the proton.

Rutherford

Mar 7, 1911

He discovered that atoms had a nucleus. The previous model stated that electrons were stuck inside of the proton. He used the Gold Foil experiment. He named his atom the Rutherford atom. It had a proton in the middle and electrons around it.

Bohr

Mar 7, 1913

Bohr found that electrons orbited around a nucleous. The previous model stated that the electrons just were still around the nucleus. He found this from his studies and research. He called his model the Bohr model.

Heisenberg and Schrodinger

Mar 7, 1926

They discoverd that electrons don't have specific paths around a nucleus, but they mostly zig-zag around it. The used mathematical equations to find this. They're model was called the Quantum Mechanical Model. It stated that electrons didn't exactly orbit around the nucleus.