# Question Video: Understanding Interactions between Electrons and Photons Physics

When an electron in an atom moves from a higher energy level to a lower energy level, it ＿ electromagnetic radiation. [A] releases [B] absorbs.

01:30

### Video Transcript

When an electron in an atom moves from a higher energy level to a lower energy level, it blank electromagnetic radiation: 1) releases, 2) absorbs.

So in this question, we’re trying to find a word out of options one or two that best fits the blank in the first part of the question. In other words, when an electron in an atom moves from a higher energy level to a lower energy level, it either releases electromagnetic radiation or it absorbs electromagnetic radiation. So which one is it?

Well, let’s draw a quick diagram of the energy levels. Let’s say that the top line here is the higher energy level or higher 𝐸. And the bottom one is the lower energy level or lower 𝐸. Now in our scenario, we initially have an electron in a higher energy level. And then it moves down into a lower energy level.

So if this electron is going from a higher energy level to a lower energy level, then it’s losing energy because it had more energy up here and it’s got less energy down here. So something must be happening to that energy. And from the question, we can deduce that this energy turns into electromagnetic radiation.

Now if the electron is losing energy, then the energy has to go somewhere. And the electron is giving out that energy. So in other words, the electron releases energy as electromagnetic radiation. And so it looks like option one is the right answer to our question. When an electron in an atom moves from a higher energy level to a lower energy level, it releases electromagnetic radiation.