History of the Atomic Theory

By jkuhn
  • 400 BCE

    First Atomic Model

    First Atomic Model
    Democritus makes the first model of the Atom. It was just a plain round sphere at this time.

  • John Dalton Releases Newer Model

    John Dalton Releases Newer Model
    Dalton discovered that Elements can only combine Atomically. The Model was only slightly different.

  • The Electron is discovered

    The Electron is discovered
    Thomson discovers the electron with an experiment with a Cathode ray tube.

  • Rutherford overturned Thomson's theory

    Rutherford overturned Thomson's theory
    Rutherford proves Thomson's Plum Pudding theory wrong with his gold foil experiment.

  • Bohr proposes new theory

    Bohr proposes new theory
    Bohr stated that the electron traveled on a steady orbit around the nucleus of the atom.

  • Chadwick discovers the Nuetron

    Chadwick discovers the Nuetron
    James Chadwick discovers the Neutron by going through Ruterford' s records during his expirment.