Stylised atom with three bohr model orbits and stylised nucleus

Evolution of the atom

  • 400 BCE

    Democritus

    Democritus
  • John Dalton

    John Dalton
    In John Dalton's experiment he wanted to see how much water vapor could be absorbed by air at different temperatures. John Dalton said an atom of a single element has a certain weight and are identical to other atoms of the same element.
  • JJ Thomson

    JJ Thomson
    In JJ Thomson's experiment he used a cathode ray tube and electrically charged plates which deflected the rays. JJ Thomson called his atomic model the plum pudding model.
  • Ernest Rutherford

    Ernest Rutherford
    In Ernest Rutherford's experiment he shot alpha particles at a thin sheet of gold foil. Ernest Rutherford expected the alpha particles to pass right through the gold foil, but some particles bounced off with great force. The atomic model Rutherford made is still the one we use today.
  • Niels Bohr

    Niels Bohr
    Niels Bohr came up with electron shells and created a new model with electron shells and energy levels.
  • Erwin Schrodinger

    Erwin Schrodinger
    Erwin Schrodinger came up with electron clouds, which is an area in an atom where electrons most likely are.