Question

why sky is blue?5 mark​

Answer 1

Answer:

due to dispersion of light

Explanation:

Gases and particles in Earth's atmosphere scatter sunlight in all directions. Blue light is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time

we know that when we pass light through prism the light dispersss into 7 colours

Answer 2

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★ Why the sky is blue?

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➝ The blue colour of the sky is due to the scattering of sunlight by the molecules of the atmosphere. As sunlight passes through atmosphere, the nitrogen and oxygen molecules of air absorb some amount of sunlight and re-emit it. The free gasmolecules scatter light in all directions. But scattering is preferential.

According to Rayleigh's law of scattering, the intensity of scattered light,

I = $\dfrac{1}{λ}$

So, the light at the short wavelength (blue) end of the visible spectrum is scattered about ten times more than the light at the long wavelength (red) end.

When we look at the sky, the scattered light enters our eyes and this light contains blue colour in a larger proportion. That is why the sky appears blue.

⭐ Role of Atmosphere

If the earth had no atmosphere, there would be no scattering of light, the sky would appear black and stars could be seen during day hours. This is what astronauts actually observe at heights 20 km above the earth where the atmosphere becomes quite thin or on the moon which has no atmosphere.

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