Atomic Structure Timeline

Timeline created by jessikamitchell
  • 340

    Aristotle

    Aristotle
    Aristotle describes his idea of five elements of Matter. Aristotle believed that all matter was made up either of one of the elements of water air earth and fire or combinations of these four elements, with the exception of stars and planets which were made of aether
  • 460

    Democritus

    Democritus
    Democritus developed the idea of an atom.
  • Antoine Lavoisier

    Antoine Lavoisier
    Lavoisier observes that heating mercuric oxide produces metallic mercury.
  • John Dalton

    John Dalton
    He thus enunciated Gay-Lussac's law or J.A.C. Charles's law, published in 1802 came up with his own atomic theory.
  • Marie & Pierre Curie

    Marie & Pierre Curie
    They established that the heavy element thorium was radioactive and discovered two new elements: polonium and radium.
  • Henri Becquerel

    Henri Becquerel
    Henri Becquerel researched the newly discovered X-rays it led to studies of how uranium salts are influenced by light.
  • J.J. Thomson

    J.J. Thomson
    He discovered the atom.
  • Ernest Rutherford

    Ernest Rutherford
    He discovered alpha and beta rays
  • Max Planck

    Max Planck
    Max Planck discovered the quantum physics/theory.
  • Niels Bohr

    Niels Bohr
    Niels Bohr proposed a theory for the hydrogen atom based on quantumtheory that energy is transferred only in certain well defined quantities.
  • Henry Moseley

    Henry Moseley
    Observed the properties of x-rays from about a dozen consecutive elements in the periodic table. In doing so, he discovered that the wavelength of the x-rays became shorter as the atomic weight increased.
  • Robert Millikan

    Robert Millikan
    He discovered the charge and mass values or an electron.
  • Werner Heisenberg

    Werner Heisenberg
    Discovered a way to formulate quantum mechanics in terms of matrices.
  • Erwin Schrodinger

    Erwin Schrodinger
    A powerful model of the atom was developed by Erwin Schrödinger.
  • James Chadwick

    James Chadwick
    James Chadwick used scattering data to calculate the mass of this neutral particle to discover the neutron.