What is responsible for the blue sky?

Gasses and particles in Earth's atmosphere scatter sunlight in all directions. Blue light is scattered more than other colors because it travels as shorter smaller waves. This it why we see a blue sky most of the time

Explanation:

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sun shine

Explanation:

A clear cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more than they scatter red light. When we look towards the sun at sunset, we see red and orange colours because the blue light has been scattered out and away from the line of sight.