Alpha-Scattering Experiment

• Plum pudding model

  An atom is a ball of positive charge with negative electrons embedded in it
• Alpha scattering experiment

  1. Scientists took a piece of gold foil

  2. Fired tiny positive alpha particles at the gold foil

  3. Most alpha particles passed straight through the gold foil

  4. Some alpha particles were deflected

  5. Some alpha particles bounced straight back
• Results of alpha scattering experiment

  • Atoms are mainly empty space
  • Center of atom has a positive charge
  • Center of atom contains a great deal of mass
• Results of alpha scattering experiment

  Led to the nuclear model replacing the plum pudding model
• Nuclear model

  Most of the atom is empty space, with a tiny positive nucleus containing most of the mass, and negative electrons around the edge
• The nuclear model of atomic structure replaced the plum pudding model