Alpha Scattering and The Nuclear Model

• What experiment is used to work out the nuclear model of atomic structure?

  The alpha scattering experiment
• What did ancient Greeks believe about atoms?

  Atoms are tiny spheres that can't be divided
• Why was the discovery of electrons significant?

  It showed atoms have an internal structure
• What model did scientists propose after discovering electrons?

  The plum pudding model
• What does the plum pudding model suggest about atoms?

  Atoms are a ball of positive charge with electrons
• What material did scientists use for the alpha scattering experiment?

  Gold foil
• Why was gold chosen for the alpha scattering experiment?

  It can be hammered into very thin foil
• What are alpha particles?

  Particles with a positive charge
• What did scientists observe about most alpha particles in the experiment?

  They passed straight through the gold foil
• What did the deflection of some alpha particles indicate?

  The center of the atom has a positive charge
• What does it mean if alpha particles bounce straight back?

  The mass of the atom is concentrated in the nucleus
• What is the central part of an atom called?

  The nucleus
• What did scientists replace the plum pudding model with?

  The nuclear model
• What did Neil Bohr propose about electrons?

  Electrons orbit the nucleus at specific distances
• What are the orbits of electrons called?

  Energy levels or shells
• What particles were discovered in the nucleus years later?

  Protons and neutrons
• What charge do neutrons have?

  They are neutral
• What are the key components of the nuclear model of atomic structure?

  • Nucleus at the center
  • Contains protons (positive charge)
  • Contains neutrons (neutral charge)
  • Electrons orbiting in energy levels
• What were the implications of the alpha scattering experiment results?

  • Atoms are mostly empty space
  • Positive charge concentrated in the nucleus
  • Mass of the atom is in the nucleus
• What are the historical developments in atomic theory?

  1. Ancient Greeks: Atoms as indivisible spheres
  2. Discovery of electrons in 1897
  3. Plum pudding model proposed
  4. Alpha scattering experiment conducted
  5. Nuclear model established
  6. Discovery of protons and neutrons