Development of the atom

By Nas315
  • 440 BCE

    Democritus

    Democritus
    everything in the world was made up of tiny particles surrounded by empty space

  • John Dalton

    John Dalton
    atoms are tiny, indestructible particles, with no internal structure

  • J.J. Thomson

    J.J. Thomson
    atoms are uniform compact spheres filled with negatively charged electrons

  • Robert Millikan

    Robert Millikan
    found the mass and charge of the electron through his oil drop experiment

  • Ernest Rutherford

    Ernest Rutherford
    atoms consist largely of empty space with just a few electrons while most of the mass was concentrated in the center of the nucleus.

  • Niels Bohr

    Niels Bohr
    electrons orbit the nucleus at fixed energies and distances

  • Werner Heisenburg

    Werner Heisenburg
    It was impossible to determine both the exact position and speed of an electron as it moved around an atom

  • James Chadwick

    James Chadwick
    confirmed the existence of neutrons, which have no charge