• 400


    First model of atom; first to think about an atom.
  • 400


    Only 4 elements; opposed Democritus' theory.
  • 500


    Everything is made of something.
  • Issac Newton

    3 laws of motion.
  • John Dalton

    Dalton's Atomic Theory.
  • JJ Thomson

    Discovered electron; used rathode ray tube.
  • Rutherford

    Atoms have + charges in a small, dense nucleus.
  • Niels Bohr

    Electrons travel on rings. Takes evergy to move from ring to ring.
  • Schroedinger

    Described a cloudlike region where electrons are liekly found.
  • John Chadwick

    Discovered the neutron. Noticed odd difference in masses.
  • Thales Of Miletus

    Noticed static. Paved way for future discoveries.
  • Period: to