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History of an atom

By Iaaa
  • 400 BCE

    Democritus

    Democritus
    if you take a piece of matter
    and divide it and continue to divide it you will
    eventually come to a point where you could not
    divide it any more. This fundamental or basic unit was what Democritus called an
    atom. In 400 bc. He called this the theory of the universe.

  • John dalton

    John dalton
    John Dalton was the first to adapt Democritus’ theory into the first modern atomic model.
    1. All matter consists of tiny particles called atoms
    2. Atoms are indestructible and unchangeable

  • JJ Thompson

    JJ Thompson
    J.J Thomson was a physicist who is credited for discovering the electron. He used his research on cathode ray tube technology in this discovery.

  • Ernest Rutherford

    Ernest Rutherford
    Ernest Rutherford was not convinced about the model of the atom proposed by Thomson. He thus set up his now famous Gold Foil Experiment.
    1. He fired alpha particles (positively charged) at a gold foil.
    He said that there must be a positive centre of the foil. He called this centre the nucleus.

  • Niels Bohr

    Niels Bohr
    Niels Bohr agreed with the planetary model of the atom, but also knew that it had a few flaws. Using his knowledge of energy and quantum physics he was able to perfect Rutherford’s model. He was able to answer why the electrons did not collapse into the nucleus.