What is meant by scattering of light? Mention the factor on which it depends. Explain why the colour of the clear sky is blue? An astronaut in space finds the sky to be dark. Explain the reason for this observation.

(N/A) $(i)$ Scattering of light is the phenomenon in which light rays deviate from their straight path upon striking small particles such as dust,air molecules,or other impurities in the atmosphere.
$(ii)$ The extent of scattering depends primarily on the size of the particles. Very fine particles scatter mainly blue light of shorter wavelengths,while larger particles scatter light of longer wavelengths.
$(iii)$ As sunlight passes through the atmosphere,the fine particles in the air scatter the blue component of white light more strongly than the red component due to its shorter wavelength. This scattered blue light reaches our eyes,making the sky appear blue.
$(iv)$ In space,there is no atmosphere and therefore no particles (like air molecules or dust) to scatter sunlight. Since no light reaches the astronaut's eyes from the sky,it appears dark.