Atomic Theory Timeline

  • 350 BCE

    Democritus

    Theorized that matter was made of small, indivisible particles which he named atomos
  • Antoine Lavoisier

    The Law of Conservation of Mass
  • Joseph Proust

    The Law of Definite Proportions
  • John Dalton

    Created the Law of Multiple proportions, which led to the Atomic Theory
  • Dimitri Mendeleev

    Periodic law, and first draft of periodic table
  • J. J. Thomson

    Cathode ray experiments which led to discovery of electron
  • Ernest Rutherford

    Gold foil Experiment, which led to the Nuclear Theory
  • James Chadwick

    Discovered Neutrons
  • Neil Bohr

    Bohr model
  • Henry Moseley

    Atomic number

Want to make a timeline like this?

Use Timetoast to turn dates, events, milestones, and phases into a clear visual timeline you can build and share. Timetoast is a timeline maker for work, school, research, and stories.