Timeline of contributions to the Atomic Model.
Discovers that Atoms are impenetrable and can't be divided.
Discovers four earthly elements:
Earth, Fire, Water, Air
Discovers one heavenly element:
Published a table with the atomic weights of six elements:
Hydrogen, Oxygen, Nitrogen, Carbon, Sulfur, Phosphorus. He also developed the Invisible Solid Sphere Model
Discovered negatively charged "corpuscles" and created the Plum Pudding Model
Discovered the charge and mass of the electron using an oil drop experiment.
Demonstrated radioactivity was often spontaneous disintegration. He also developed the Planetary Model and the Nuclear Model.
Worked on the Quantum Theory
Model of Atomic Structure
Internal Clock of the Electron
Work on quantum theory
Published his uncertanty principle
He discovered neutrons