1. Atomic Model Timeline

2. Dalton’s Model 1808 Atoms: Extremely small dense particles Indivisible
Combine together to form different compounds

3. Electron Discovery late 1897
Cathode ray tube
The discovery of the electron
Atom has very light negatively
charged particles (electrons)
Atoms are neutral, so there must
be another positive charge

4. J.J. Thomson (Plum Pudding Model) 1904

5. Rutherford Model (Gold Foil Exp.) 1911

6. Rutherford Model (Gold Foil Exp.) 1911
Most of the positive rays passed to the other side
Conclusion: Most of the atom is space
Some very few rays deflected back
Conclusion: There must be a very dense small particle inside the atom(Nucleus)
Some very few rays deflected with small angle
Conclusion: the small dense nucleus must be positively charged, that caused repulsion with the positive rays passing near it.

7. Bohr’s Model 1913 (Orbits)

8. Schrodinger Model (Orbitals)

9. Schrodinger Model 1920