Atomic Theory

Atomic Theory

1. John Dalton

   • 1808
   • "All atoms are made up of small individual particles"
   • Atoms of the same element are identical
   • atoms rearranged in a chemical reaction
   • Compounds are 2 or more atoms together

2. J.J Thomson

   • 1987
   • Electron
   • Plum Pudding
     • negative electrons in a sphere of positive
   • Atom is neutral

3. Ernest Rutherford

   • 1913
   • discovery of nucleus
   • Protons = Electrons
   • electrons are around a positive nucleus
   • protons are 2000 times heavier than electrons
   • most mass is in the nucleus

4. James Chadwick

   • 1932
   • neutron