Timeline

By yaseenshaikh
  • 400 BCE

    Democritus

    Democritus
    Proposed the idea that matter was not infinitely divisible;
    Came up with atom
  • 351 BCE

    Aristotle and Plato

    Aristotle and Plato
    Believed that no empty space existed,
    and that all things were created of air, water, fire, earth

  • Dalton

    Dalton
    Created the Atomic Theory of Matter Proposed explanation for: law of conservation of mass

  • Goldstein

    Goldstein
    Discovered positive anode ray

  • Becquerel

    Discovered three types of radioactivity

  • J.J. Thomson

    Created plum pudding model.

  • Nagoaka

    Suggested electrons orbit one central nucleus

  • Rutherford

    Rutherford
    Proposed that the atom is mostly empty space, with a central nucleus. (Rutherford Model)

  • Robert Millikan

    Robert Millikan
    Found electron’s charge and mass

  • James Chadwick

    James Chadwick
    Discovered the neutron