Kirstie Geren

  • 300

    Disagreeing to the Atom Theory

    Disagreeing to the Atom Theory
    Aristotle didn't believe that atoms existed. He thought that everything and everyone was made up of the natural elements in the earth such as water and fire.
  • 400

    Discovery of the Atom

    Discovery of the Atom
    Democritus discovered the idea of molecules that everything is made of. This occured in 400 B.C.
  • Dalton's Theory

    Dalton believes that mass is based upon small spherical atoms.
  • Discovery of Thallium (element)

    Crookes discovers the element ,thallium, using the crookes tube.
  • First Periodic Table

    Mendeleev creates the first organized periodic table.
  • Discovery of the Electron

    J. J. Thomson discovered the electron using cathode rays with the Crookes Tube.
  • Discovery of the Proton

    Rutherford discovers a positive force inside the nucleus of the atom.
  • Discovery of the Neutron

    Chadwick discovers the neutron after noticing a strange amount of mass that protons and electrons were not taking up.
  • Period: to

    Contributions to Chemistry