Rutherford Scattering

Remember: “Gold Foil Experiment Revealed the Heart of the Atom”

• Rutherford used gold foil because of its thinness and abundance of electrons.
• Alpha particles scattered at large angles due to the presence of a tiny, dense nucleus.
• Scattering angles provided insights into the relationship between impact parameter and nuclear radius.
• Nuclear radius found to be 100,000 times smaller than atomic radius, indicating most of the atom’s volume is empty space.

Introduction to Bohr Model

Remember: “Bohr’s Energy Levels: A Quantum Leap in Atomic Understanding”

• Bohr refined Rutherford’s model by introducing energy levels and quantized energy states.
• Electrons can only occupy certain discrete orbits with specific radii determined by their energy levels.
• When electrons jump between energy levels, emission or absorption of photons occurs, resulting in spectral lines.
• Bohr’s model successfully explained the Rydberg formula.

Additional Points

Remember: “Atomic Zoo and Energy Units”

• Atomic number (Z): Number of protons, determines an element’s identity.
• Mass number (A): Sum of protons and neutrons in an atom’s nucleus.
• Isotopes: Same element with varying numbers of neutrons (different A but same Z).
• Isobars: Different elements with the same mass number (same A but different Z).
• Isotones: Different elements with the same number of neutrons (same N but different Z).
• Electron volts (eV): Energy unit常用 in atomic physics, equivalent to energy gained by an electron accelerating through a potential of 1 volt.
• Atomic units (a.u.): Convenient system derived from fundamental constants where:
  • e(electron charge) = 1
  • m(electron mass) = 1
  • 4πε0 = 1