The sky looks blue because of

• A. Reflection
• B. Scattering
• C. Absorption
• D. Refraction

Answer: (B)

Light from the sun is white, containing all colors. When it enters the atmosphere, the gas molecules scatter shorter wavelengths of light (blue and violet) more than longer wavelengths. This scattered blue light comes from every direction, so the sky appears blue. Violet is scattered even more, but the sky doesn’t look violet because the sun emits less violet and the atmosphere absorbs much of it, while our eyes are more sensitive to blue.

The other ideas don’t explain the color: reflection would mean the sky is mirroring something else, absorption would remove colors rather than create the blue tint, and refraction changes the direction of light but doesn’t produce a blue sky across the whole dome.