Atom diagram

Atomic Theory Scientists

  • 400


    Democritus found the atom and had a theory that the atom was indivisble. This was later proven wrong.
  • John Dalton

    John Dalton
    Dalton had a theory that matter was composed of different atoms of different weights. He proposed the first atomic theory with spherical masses in motion. He had 3 points:
    1. All matter consisted of tiny particles 2. Atoms are indivisble
    3. Elements are categorised by the mass of the atom.
  • G.J Stoney

    G.J Stoney
    Stoney had a theory that electricity was made of lots of negative particles, soon these particles were called electrons and are still called electrons today.
  • J.J Thomson

    J.J Thomson
    Thomson discovered electrons and this helped people realise that atoms ARE in fact divisble and that electrons were distributed in a sea of positive charge.
  • Max Planck

    Max Planck
    Planck is the founder of the quantum theory and is one of the most important physicists in the 20th century
  • Hantaro Nagaoka

    Hantaro Nagaoka
    Nagaoka proposed a model which had a positively charged centre and had electrons revolving around it bound by an electrostatic force. This helps us understand how the electrons affect the nucleus and the whole atom.
  • Robert A. Millikan

    Robert A. Millikan
    Millikan discovered the mass and charge of electrons. This led him to figuring out that the weight of an electron is 1836 times smaller than a hydrogen atom.
  • Ernest Rutherford

    Ernest Rutherford
    Discovered the nucleus and how atoms bond together in definite proportions. Rutherford proposed that the positive charge must be localized, concentrated in a small nucleus.
  • H.G.J Moseley

    H.G.J Moseley
    He created the Moseley Law. The law helped advance chemistry by immediately sorting the elements of the periodic table in a more logical order.
  • Niels Bohr

    Niels Bohr
    Bohr found that electrons moved around the nucleus of the atom and that electrons move around the nucleus of the atom in restricted orbits. Bohr also found the solution to the stability of the nuclear model of the atom.
  • James Chadwick

    James Chadwick
    Chadwick proved that the nucleus contain neutral particles. Chadwick proved that there were such things as neutral particles in the nucleus and they are now known as neutrons.