Atomic Model Timeline

By geeky3100
  • 400 BCE

    Democritus

    Democritus
    In 400 bc, Democritus had the theory that the universe had 2 elements, atoms and the void they move in. His structure was a small ball of matter.

  • John Dalton

    John Dalton
    He believed they were solid atoms.

  • J.J Thomson

    J.J Thomson
    Found electrons in his Atom altering the previous models. This became the Plum Pudding Model because he proposed an atom with positive "pudding" with negatively charged "plums"

  • Max Planck

    Max Planck
    He expanded the way we look at the atom with the Atomic Theory. This was used to explain hot, glowing matter.

  • Robert Millikan

    Robert Millikan
    Known for his Oil Drop experiment, Millikan tested and determined the mass and charge of the atom.

  • Ernest Rutherford

    Ernest Rutherford
    Rutherford discovered through his Gold Foil Experiment, that there were negatively charged which was different from the nucleus of the atom.

  • Niels Bohr

    Niels Bohr
    His atom had orbitals which built up with the energy.

  • Werner Heisenberg

    Werner Heisenberg
    Looked at atoms as a formula, determining that you cannot know the velocity and position of the particle simoultaniously.

  • Erwin Schrodinger

    Erwin Schrodinger
    He introduced Wave Mechanics as a mathematical way to see the atom. He proposed the Quantum Mechancial Model.

  • James Chadwick

    James Chadwick
    He discovered the neutron during his experiments leading up to his new atomic model.