Came up with idea of atom, model had no protons, neutrons, or election. Solid (small pointy atoms), liquid (large round atoms), oils (fine small atoms that could slip past each other).
Could understand things/figure out things by just looking at them (Earth, fire, water, and wind). All one material, no particles at all.
Came up with law of conservation of mass. Hinted at rearrangement of matter during reactions. Named oxygen and hydrogen (1778, 1783)
All matter is made of atoms, all atoms are identical in mass and properties, chemical reaction is a rearrangement of atoms, compounds are formed by combination of 2 or more atoms (even numbered ratios)
Discovered electrons. Was first scientist to show that the atom was made of even smaller things.
Determined the charge of an electron. Proved Einstein's photoelectric equation.
Discovered protons and the nucleus. Also showed that atoms are mostly empty space.
Improved Rutherford's model. He proposed that electrons move around the nucleus in shells.
Proposed that electrons absorb and emit radiation of fixed wavelengths when jumping between fixed orbits around a nucleus.
Proposed that elections are arranged in concrete circular orbits around the nucleus.
Discovered the neutron. Said electrons orbited the neutrons and protons.
Gell-mann proposed that quarks make up protons and neutrons.