Pre-Assignment

1. Define the parameter, α, in terms of particle diameter vs. wavelength and particle circumference vs. wavelength.
2. Why is the colour of the sky orange-red during the sunrise and sunset?
3. What will be scattering pattern for N2 molecule?
4. "When a white light beam is passed through a glass cube containing small dispersed particles, the cube appears either bluish or reddish when viewed from different directions." Justify it.
5. In the Rayleigh regime, compare scattering intensities of 450 nm wavelength (blue) and 650 nm (red) lights.

Post-Assignment

1. What happens if one stirs vigorously to dissolve soap powder in water?
2. Though smaller N2 and O2 molecules in the atmosphere can scatter light, why don't we see Tyndall effect in sugar solution which have larger sugar molecules?
3. What is the reason for showing Tyndall effect by soap solution?
4. Arrange the following three samples in increasing order of particle size: salt, detergent & Fe(OH)3 colloid in water.
5. Do we always need colloids to observe the light scattering phenomenon?