Stars are twinkling due to

At sunrise or sunset,the sun looks more red than at midday because

Discuss the natural phenomena that occur due to sunlight.

During the scattering of light, the amount of scattering is inversely proportional to the . . . . . . of the wavelength of light.

If the scattering intensity of a liquid is $8 \text{ units}$ at a wavelength of $500 \text{ nm}$, then the scattering intensity at a wavelength of $400 \text{ nm}$ will be approximately: (in $\text{ units}$)

The Sun is visible before actual sunrise and after actual sunset for some time. Explain this phenomenon.