• 384


    384-322 BC, was tutored by Alexander the Great, he beleived in the four elements air, earth, water, and fire.
  • 400


    histheory revovleved around the atoms that are present in the atmosphere. He learned from the author Leucippus, also Aristotle.
  • John Dalton

    John Dalton
    discovered that oxygen and carbon combined to make two compounds that had thier own weight ration of oxyygento carbon
  • Robert Milikan

    Robert Milikan
    used a small drop of oil to measure the incremental charge of an electron. he also showed that the electron charge was a single value.
  • Henri Becquerel

    Henri Becquerel
    Was a proffessor at the French Academy of Science.
    EXPERIMENT: wrapped a photographic plate with emulsion with two sheets of thick black paper, so that the plate itlsf is out of the sun, then you put it into the sun wich results in a black neggative. this is how he helpped in the development of atomic history.
  • J.J. Thompson

    J.J. Thompson
    Discovered the electron. He did this using experiments designed to study electric discharge. He also sugesttested that the atom should be a sphere.
  • Ernest Rutherford

    Ernest Rutherford
    described that the atom had a central positive nucleus surrounded by neggative electrons. Rutherford discoverd that most of an atom is made up of empty space
  • Neils Bohr

    Neils Bohr
    the Bohr Model was a much simpler version of quantum mechanics. Demonstrated positive and electric charges
  • Quantum Model

    Quantum Model
    A probability area in an electron might be located in.
  • James Cahdwick

    James Cahdwick
    in 1932 Chadwich discovered the third type of subatomic particle
  • Marie and Pierre Curie

    Marie and Pierre Curie
    figured out how to find the atomic mass of an atom