Question

the sky looks red at sunrise and sunset why

Answer 1

The sky appears red at sunset and sunrise due to scattering of light...
When the sunlight enters the earth's atmosphere than, shorter wavelength light are scattered by atmospheric particles an the light that reaches our eyes is red.....
And also the sunlight coming from horizon has to travel longer distance in atmosphere

SO the sun appears red at sunset and sunrise

Hope it helps you dear ☺️☺️

Answer 2

at the time of sunrise and sunset ,the light from sun has to travel the longest distance of atmosphere to reach the observer .since the blue light of shorter wavelength is scattered more,much of it is lost,while the red light of long wavelength is scattered a little, so it is not much lost .thus blue light is almost absent in sunlight reaching the observer and only the red light reaches us.as a result ,the sun and the region near by it ,is seen red.