Can anyone can tell me why sky is blue
Answers
because it reflects the ocean; because oxygen is a blue-colored gas; because sunlight has a blue tint — while the right answer is often thoroughly overlooked. In truth, the reason the sky is blue is because of three simple factors put together: that sunlight is made out of light of many different wavelengths, that Earth's atmosphere is made out of molecules that scatter different-wavelength light by different amounts, and the sensitivity of our eyes. Put these three things together, and a blue sky is inevitable. Here's how it all comes together.
Light of many different wavelengths, not all of which are visible, are emitted by the Sun. The atmosphere affects every unique wavelength differently, resulting in the full suite of optical phenomena we can observe.
Sunlight is made up of all the different colors of light... and then some! The photosphere of our Sun is so hot, at nearly 6,000 K, that it emits a wide spectrum of light, from ultraviolet at the highest energies and into the visible, from violet all the way to red, and then deep into the infrared portion of the spectrum. The highest energy light is also the shortest-wavelength (and high-frequency) light, while the lower energy light has longer-wavelengths (and low-frequencies) than the high-energy counterparts. When you see a prism split up sunlight into its individual components, the reason the light splits at all is because of the fact that redder light has a longer wavelength than the bluer light.