Alpha-Scattering Experiment

• What is the plum pudding model of atomic structure?

  The plum pudding model describes an atom as a ball of positive charge with negative electrons embedded in it.
• Why was the plum pudding model accepted for hundreds of years?

  It was accepted because it aligned with the belief that atoms were indivisible spheres.
• What significant discovery was made in 1897 regarding atomic structure?

  Scientists discovered that atoms contain tiny negative particles called electrons.
• What led to the development of the nuclear model of atomic structure?

  • Discovery of electrons in atoms
  • Alpha scattering experiment results
  • Most alpha particles passed through gold foil
  • Some alpha particles were deflected
  • Some alpha particles bounced back
• What is the purpose of the alpha scattering experiment?

  The alpha scattering experiment was conducted to test the validity of the plum pudding model.
• Why did scientists use gold foil in the alpha scattering experiment?

  Because gold can be made into very thin foil, just a few atoms thick.
• What charge do alpha particles have?

  Alpha particles have a positive charge.
• What conclusion did scientists draw from the fact that most alpha particles passed straight through the gold foil?

  Atoms are mainly empty space.
• What does it imply if some alpha particles were deflected during the experiment?

  It implies that the center of the atom has a positive charge.
• What does it mean if some alpha particles bounced straight back off the gold foil?

  It means the center of the atom contains a great deal of mass.
• What are the key features of the nuclear model of atomic structure?

  • Most of the atom is empty space
  • A tiny positive nucleus at the center
  • The nucleus contains most of the mass of the atom
  • Negative electrons orbit around the nucleus
• What replaced the plum pudding model?

  The nuclear model replaced the plum pudding model.