Why does clear sky appear blue?

When sunlight enters the earth 's atmosphere ' the atoms or molecules of the gasses present in the atmospherescatter this light. Since wavelength of red colour is larger than the wavelengths of other colours in sunlight ' so red colour is scattered less. Violet colour is scattered d most followed by blue,green, yellow, orange& redcolours resp. Our eye is more sensitive to the blue light than the violet light. Therefore, scattered light in the sky contains blue colour in plenty & hence the clear sky appears blue.