Changes in the Atom

Timeline created by cdimineshed
  • 400

    B.C. Democritus

    B.C.  Democritus
    He Concluded that all matter consisted of atoms. These atoms could not be divided any further and were all comprised of the same primary matter.
  • Antoine Lavoisier

    Introduced Quantative Chemistry and Internal Combustion
  • Joseph Proust

    He Created the Definite law of proportions
  • John Dalton

    Created Dalton's Atomic Theory (As Listed)
  • Dmitri Mendeleev

    Created the first Periodic table of elements
  • Max Planck

    Created the Planck Constant, Planck Postulate and the Planck's law of black body radiation.
  • Henri Becquerel

    Henri Becquerel
    Henri accidently discovers Radioactivity while experimenting with Phospheresence in Uranium salts.
  • Marie Curie

    Made contributions to the discovery of radioactivity
  • J.J. Thomson

    J.J. Thomson discovers the electron
  • Hans Geiger

    Hans Geiger
    Discovered the Atomic Nucleus. Invented the "Geiger Counter"
  • Niels Bohr

    Niels Bohr
    Worked with the United States on the "Manhattan Project"
  • Erwin Schrodinger

    He came up with schrodinger's equation which helped predict energy of atoms and their electrons.
  • James Chadwick

    James Chadwick
    He worked on the ionization of phosphorus and also on the photo-chemical reaction of carbon monoxide and chlorine. James was also affiliated with the "Manhattan Project"
  • Robert A. MIllikan

    Robert A. MIllikan
    Mass of electon determined
  • H.J.G. Mosely

    H.J.G. Mosely
    Atominc Number determined, Reorganized the periodic table of elements.
  • Earnest Rutherford

    Confirmed the excistence of the Proton, Proposed the idea of the nuetron.
  • James Chadwick

    James Chadwick
    Nuetron identified