Atomic Model Timeline

  • 300


    Aristotle is credited for discovering the four "elements", which he named air, fire, water, and earth. He believed in reasoning in substitution of scientific experiments.
  • 400

    Democritus Atomic model

    Democritus Atomic model
  • Antoine Lavoisier

    Antoine Lavoisier
  • Dalton Atomic Theory

    Dalton Atomic Theory
  • Henri Becquerel

    Henri Becquerel
  • J.J. Thomson Model

    J.J. Thomson Model
  • Max Planck

    Max Planck
  • Hantaro Nagaoka

    Hantaro Nagaoka
  • Robert Millikan

    Robert Millikan
  • Ernest Rutherford

    Ernest Rutherford
  • Niels Bohr

    Niels Bohr
    electrons: proposed that electrons:
    - orbit the nucleus without losing energy;
    - could move only in fixed orbits of specific energies.
    - Electrons with low energy would orbit closer to the nucleus while electrons with high energy orbit further from the nucleus.
  • Louis deBrogile

    Louis deBrogile
  • Erwin Schrodinger

    Erwin Schrodinger
  • Werner Heisenburg quantum mechanics

    Werner Heisenburg quantum mechanics
  • James Chadwick

    James Chadwick