Development of atomic theory

Timeline created by samira2001
  • 460


    democritus said that atoms are unccutable particles that are hard, small and they move around.
  • John Dalton

    John Dalton
    John Dalton found out that all elements are are combined in specific proportions. He said that: All substances are made out of atoms, atoms can not be didvided or destroyed, and that atoms are formed together to make new substances.
  • J.J Thompson

    J.J Thompson
    J.J Thompson performed the cathode-ray experiment and an electrical beam was drawn to a positivly charged plate. His model is known as the plum puddig model.
  • Ernest Rutherford

    Ernest Rutherford
    Ernest Rutherford did the gold-foil experiment to isolate the positive particles in atoms. He dicided that atoms are mostly empty space and that in the middle of an atom is an nucleur.
  • Niels Bohr

    Niels Bohr
    Niels Bohr found out that the elctrons are travelling in a fixed path. Scientists now still use Bohrs method to show the number of electrons in each orbit around the nucleur.
  • Schrodinger and Heisenberg

    Schrodinger and Heisenberg
    They both found out that electrons dont travel in fixed paths. The exact path of an electron can not be predicted. There are parts inside the atom where electrons likely can be found.