Which component of sunlight is scattered away when the sun appears red at sunrise or sunset?

Draw a neat and labelled diagram of the experimental set up for observing the scattering of light in a colloidal solution of sulphur to show how the sky appears blue, and the sun appears red at sunrise and sunset.

Out of blue light and red light, which one is scattered more easily?

What causes the scattering of blue component of sunlight in the atmosphere?

The blue colour of sky is due to: