history of the atom

By bastida09
  • 400

    Aristotle

    Aristotle
    He developed the theory that all matter consisted of four elements: Earth, Air, Water and Fire. Aound the year 400B.C
  • Period: 400 to 500

    history of atoms

  • 440

    Democritus

    Democritus
    He discovered the idea of an atom 440B.C

  • Lavoisier

    Lavoisier
    discovered oxygen in 1778 Hydrogen in 1783. and said that matter cannot destroyed during a chemical reaction even tho its physical properties are changed

  • proust

    proust
    law of definite proportions in 1794
  • Period: to

    history of the atom

  • Dalton

    Dalton
    discovered Atomic Therory and the closest person to come up of what a atom looks like. 1803

  • crookes

    crookes
    element thallium 1961

  • thomson

    thomson
    discovered electrons in 1897

  • Becquerel

    Becquerel
    founded radioactvity by accident in 1898. (Bq)

  • Curie

    Curie
    Discovered Radium & Poloniem in 1898

  • millikam

    millikam
    found the charge of an electron. 1909

  • moseley

    moseley
    came up with the periodic table and atomic number 1912

  • Bohr

    Bohr
    atomic structure in 1913

  • Ruthrtford

    Ruthrtford
    discovered protons in 1919

  • Chadwick

    Chadwick
    Discovered the nuetron in 1932