Question

1. Assertion: The scattering of longer wavelengths of light increases as the size of the particles increases.

Reason: Large particles scatter lights of all wavelengths equally well.

Answer 1

Answer:

The molecules of air and other fine particles in the atmosphere have size smaller than the wavelength of visible light. These are more effective in scattering light of shorter wavelengths at the blue end. Whereas, larger particles scatter light of longer wavelengths at the red end.

Answer 2

Assertion is true and reason is also correct.

Explanation:

• Scattering of light is throwing light in various directions.
• Scattering of light is phenomenon of absorption and then re-emission of light energy.
• Light is scattered when it falls on various types of suspended particles in its path.
• In this process, colors having long wavelength will scatter the least while one having shorter wavelength scatters the most.
• Larger particles of dust and water droplets present in atmosphere are main responsible factors for scattering of sunlight due to which it appears white.
• Molecules of air and other fine particles in the atmosphere have their size smaller than the wavelength of visible light. So, they are more effective in scattering light of shorter wavelengths.

• The red light has a larger wavelength than blue light. So, when sunlight is passing through the atmosphere, the fine particles in air scatter the blue color more strongly than red.