Atomic Structure

The timeline:

500BC - Democritus

- they are indivisible: there are different types

1808 - Dalton

1897 - Thompson: Plum Pudding Model

- electrons embedded in a solid atom of positive charge

1911 - Rutherford

- discovered in alpha scattering experiment that the middle was positive and electrons were around the outside, most of the atom is space

1913 - Bohr

- electrons arranged in shells

Chadwick and Rutherford: