Atomic Timeline

  • Mar 13, 600


    Democritus made a thoery that everything is made of a particale that cannot become simpler called atomos.
  • "Atomic Theory"

    John Dalton based a new theory called the atomic theory based on Democritus' atmoms theory. He said everything was made of spherical shaped solids called atoms.
  • J.J Thompson

    J.J Thompson used a CRT to experimentally determine the charge to mass ratio (e/m) of an electron =1.759 x 10 8 coulombs/gram.
  • Uranium and Thorium

    Rutherford studied radiations emitted from uranium and thorium and named them alpha and beta.
  • Gold Foil Experiment

    Rutherford using alpha particles as atomic bullets, probed the atoms in a piece of thin (0.00006 cm) gold foil . He established that the nucleus was: very dense,very small and positively charged. He also assumed that the electrons were located outside the nucleus