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Chemistry Timeline

By ns18748
  • Niels Bohr
    1922 BCE

    Niels Bohr

    Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another.
  • JJ Thomson
    1896 BCE

    JJ Thomson

    J. J. Thomson, who discovered the electron in 1897, proposed the plum pudding model of the atom in 1904 before the discovery of the atomic nucleus in order to include the electron in the atomic model. In Thomson's model, the atom is composed of electrons.
  • Ernest Rutherford
    1895 BCE

    Ernest Rutherford

    Ernest Rutherford, 1st Baron Rutherford of Nelson was a New Zealand chemist who has become known as the. In 1911, he was the first to discover that atoms have a small charged nucleus surrounded by largely empty space, and are circled by tiny electrons, which became known as the Rutherford model (or planetary model) of the atom. He is also credited with the discovery of the proton in 1919, and hypothesized the existence of the neutron. He was awarded the Nobel Prize in Chemistry in 1908
  • John Dalton
    1776 BCE

    John Dalton

    John Dalton was an English chemist, physicist, and meteorologist. He is best known for his pioneering work in the development of modern atomic theory; and his research into colour blindness, sometimes referred to as Daltonism, in his honour.
  • Alchemists
    1200 BCE

    Alchemists

    The most persistent goals of alchemy have been the prolongation of life and the transmutation of base metals into gold. It appears that neither was accomplished, unless one credits alchemy with the consequences of modern chemotherapy and the cyclotron.
  • Demococritus
    460 BCE

    Demococritus

    According to Democritus, the atoms had shape, mass, and motion but no other qualities, such as color or flavor. These latter were supplied by the observer and were subjective