alpha scattering experiment

• Atoms


  Tiny spheres which cannot be divided (ancient Greek belief)
• In 1897, scientists discovered that atoms contain tiny negative particles called electrons
• 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

  4. Some alpha particles were deflected

  5. Some alpha particles bounced straight back
• The results of the alpha scattering experiment showed that atoms are mainly empty space because alpha partiles wentstraight through gold foil
• The results of the alpha scattering experiment showed that the centre of the atom must have a positive charge becuase some of the alpha particles deflected
• The results of the alpha scattering experiment showed that the centre of the atom must contain a great deal of mass becasue some of the alpha particles bounced straight back
• 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 replaced the plum pudding model based on the results of the alpha scattering experiment