Question

Are EM waves scattered the most when the wavelength and the obstacle have a similar size?

Answer 1

EM waves interact with matter in a similar way : on their own scale of size and time. The reason why visible light can't travel through walls ...

Answer 2

Hello mate here is your answer.

Oxygen and nitrogen in the atmosphere causes all colors of light to scatter. But because the shorter end of the visible spectrum is closer in size to oxygen and nitrogen atoms, they interact more and are scattered to a higher degree. If only the shortest visible light was scattered, the sky would look more violet than blue. But the sky blue color you see is actually of a mixture that includes green, yellow, orange, and red in decreasing intensity.

Hope it helps you.