what causes objects to emit electromagnetic radiation?

Question

I know that standard stuff that every textbook says about electromagnetic radiation. I know the different categories (x-ray, microwave, visible light, etc). I know the meaning of the words frequency and wavelength. I still don’t really understand what electromagnetic radiation IS or why objects emit it. I know that wavelength is the distance between the crests of the wave, but what ARE the crests?

In: 4

Answer 1

In general it’s a way for atoms to lose excess energy, for example it can happen when an electron goes to a lower energy state, or when various forms of nuclear decay happen.

Answer 2

In general it’s a way for atoms to lose excess energy, for example it can happen when an electron goes to a lower energy state, or when various forms of nuclear decay happen.