### Rutherford Scattering And Introduction To Bohr Model

**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