Development of the particle model

By Jordi -_-
  • 410 BCE

    Democritus

    Democritus was the first philosopher to theorise about the atom.
  • 340 BCE

    Aristotle

    Aristotle rejected the ideas of Democritus, instead believing that matter on Earth was made up of four elements – earth, air, fire and water – and the amounts of these elements determined how materials behaved. Aristotle had such an influence over people at the time that it took about 2000 years for Democritus’s theory to be re-examined.

  • John Dalton

    Dalton is credited for initiating research into modern atomic theory in 1803, more than 2000 years after Democritus first proposed his ideas on the atom. Dalton suggested that all elements, which were now arranged in the periodic table, contained atoms, and that atoms of the same element would be identical in size, shape and mass.

  • Joseph John Thomson

    Thomson was the first scientist to discover particles smaller than the atom, disproving Dalton’s and Democritus’s theories.

  • Ernest Rutherford

    In 1911, Ernest Rutherford and colleagues Hans Geiger and Ernest Marsden fired alpha particles (helium nuclei) at a thin piece of gold foil, in the famous gold foil experiment.

  • Niels Bohr