History of the atom

Cards (5)

  • John Dalton
    19th century
    Said atoms were solid spheres.
  • JJ Thomson
    1897
    Plum pudding model- atom is a ball of positive charge with negative electrons studded into it
  • Rutherford
    1909
    Alpha scattering experiment (Gold foil)- mass concentrated at the centre; the nucleus is positively charged. Most of the mass is in the nucleus. Most atoms are empty space.
  • Bohr
    1911
    Electrons are in shells orbiting the nucleus
  • Chadwick
    1940
    Discovered neutrons in the nucleus