Question

Why does the sky appear blue

Answer 1

Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.

Answer 2

There a large number of small particles in the atmosphere like dust, smoke when the sun light passes through the atmosphere the particles scatter the shorter wavelengths like blue
Thus it appears blue