What is scattering of light? Explain the different types of scattering with examples.

1. 1 · Define scattering in one line. Scattering is the process in which particles in the path of light absorb it and send it out in all directions.
2. 2 · Name the two kinds. Elastic: the frequency of scattered light is unchanged. Inelastic: the frequency changes.
3. 3 · Rayleigh scattering. By gas molecules much smaller than the wavelength; S ∝ 1/λ⁴; explains the blue sky and the reddish Sun at sunset.
4. 4 · Mie scattering. By dust, smoke, pollen and water droplets as large as the wavelength or larger; explains white clouds.
5. 5 · Tyndall scattering. By colloidal particles; the path of a sunbeam in a dusty room becomes visible.
6. 6 · Raman scattering.
   • Monochromatic light through a transparent liquid gives new frequencies.
   • Same frequency: Rayleigh lines; different frequencies: Raman lines.
   • Lower frequency: Stokes lines; higher frequency: anti-Stokes lines.
7. 7 · Real-life link. Blue sky, orange sunsets over the sea, red danger signals, the projector beam in a cinema hall.
8. 8 · Close in one line. The size of the scattering particle decides the type of scattering we see.

Scoring tip: Give each type its cause and one example. Write S ∝ 1/λ⁴ for Rayleigh, and name Stokes and anti-Stokes lines for Raman.