Question

why scattering centre are responsible for blue sky

Answer 1

the sky is blue because molecules in the air scatter blue light from the sun more than they scatter red light because blue light have shortest wavelength. 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.

Answer 2

Because the blue colour's wavelenght is shortest, therefore it scatters more.
While, other colours are also mixed in atmosphere, only because of the wave length of blue light is short it scaterrs the more.

The wavelenght of light is inversely proportional to it's scattering.