Timeline created by amaceachern
  • 322


    Aristotle didn't believe that in atoms because he thought there was no smaller part of matter. He came up with this theory in 500 B.C. People believed Aristotle's theory because it was easier to understand. Aristotle adopted this theory because of his belief in the gods and how he felt that if the gods didn't create it, it didn't exsist. Aristotle founded the scientific method.
  • Period:

    The Atom

  • 370


    One of the founders of the atomic theory. Believed that there are small, indivisible bodies which everything else is composed and that they move about in an infinite space.
  • John Dalton

    John Dalton
    Helped work on the atomic theory. Dalton performed experiments on temperature, gasses, vapours and pressures. He performed these experiments to help better understand his theories.
  • Henri Becquerel

    Henri Becquerel
    While working on a exoermient that exposed uranium-bearing crystal to sunlight, Henri discoered radioactivity. Also, he recieves 3 Nobel Peace Prizes.
  • JJ Thomson

    JJ Thomson
    Helped discover the electron and isotopes. He discovered this through the cathode rays. He also said that rays were made up of very light and negativley charged particles that were blocking atoms.
  • Ernest Rutherford

    Ernest Rutherford
    Founded two types of radio action called thorium and uranium in the experiments he performed. Also, in 1908 he was awarded a nobel peace prize in chemistry for his study in the disentigration of elements and radio substances.
  • Robert Millikan

    Robert Millikan
    Discovered the measurement of a charge in an electron. While working on an oil drop experiment of an electron, he found the charge-to-mass ratio on the electron and found the measurements.
  • Niels Bohr

    Niels Bohr
    Helped scientists better understand the atomic structure and quantom mechanic. Niels based his theory off of Rutherford's structure and discovered the quantum mechanic from the model of the structure.
  • Quantum Model

    Quantum Model
    A model that shows the area the atom might be located in. Also shows that an atom contains a nucleus, protons and electrons. this model was discovered in 1925 by two men named C.J. Davidson and John H. Germer.
  • James Chadwick

    James Chadwick
    Discovered the neutron. Also, in 1992 Chadwick discovered an unkown particle by the lack of the electric charge in the atomic nucleus.
  • Marie and Pierre Curie

    Marie and Pierre Curie
    Discovered Polonium and Radium. Discovered this by studying the field of radiology.