Atomic structure timeline

• Dalton - 1803 - discovered the atom, model - solid sphere of positive charge.
• Thomson - 1904 - discovered the electron, discovered the plum pudding model.
• Rutherford and Marsden- 1911 - discovered nucleus, nuclear model, small positively charged nucleus containing all the mass surrounded by electrons.
• Neil Bohr - 1913 - discovered electron shell, planetary model, electrons orbitting the nucleus, electrons orbiting the nucleus in shells.
• Rutherford - 1917 - protons, nucleus can be subdived into protons each with the same amount of positive charge.
• James Chadwick - 1940 - neutrons, nucleus also contained neutrons with no mass/charge.