Atomic Theory Timeline

By falconzfan4ever
  • 500

    Democritus

    Democritus
    In the 5th Century BCE, Democritus coined the term 'a-tomus', which means uncuttable

  • Dalton

    Dalton
    In 1799, Dalton stated that elements combine in definite whole-number ratios.
    At the same time, slavery was abolished in New York.

  • Dalton

    Dalton
    In 1803, Dalton stated that atoms of the same element are identical. He also stated that all matter is made of atoms

  • Mendelev

    Mendelev
    In 1869, Mendelev created the first periodic table of elements.

  • Planck

    Planck
    In 1900, Planck stated that electrons absorb and emit discrete amounts of energy called quanta.

  • Soddy

    Soddy
    In 1900, Soddy discovered isotopes.

  • Millikan

    Millikan
    In 1910, Millikan used the oil drop experiment to discover the charge of the electron.

  • Rutherford

    Rutherford
    In 1911, Rutherford used the gold foil experiment and discovered the nucleus of an atom. Also in 1911, Rutherford stated that atoms are mostly empty space except for the dense positively-charged nucleus.
    At this time, the Mexican Revolution was going on.

  • Bohr

    Bohr
    In 1912, Bohr stated that electrons travel in definite paths, called orbits.

  • Henry Moseley

    Henry Moseley
    In 1913, Henry Moseley ordered the periodic table by atomic number, fixing his predecessor’s mistakes.

  • De Broglie

    De Broglie
    In 1923, De Broglie proposed that electrons behave as light (energy) and particles (matter).
    At this time, World War I was going on.

  • Chadwick

    Chadwick
    In 1932 Chadwick discovered the neutron.
    At the same time, the Great Depression occured.

  • Teja Nekkanti

    Teja Nekkanti
    What a stud!

  • Lincoln Toiaivao

    Lincoln Toiaivao
    Hes single and ready to mingle