Answer the following question given this paragraph: 

Electrons are located at fixed distances from the nucleus, called energy levels. You can see the first three energy levels in the Figure below . The diagram also shows the maximum possible number of electrons at each energy level.


Q: Electrons are located at fixed distances from the nucleus, what are they called?

 Choices:

- Energy layers

- Positive levels

- energy concentrations

- energy levels

A:
energy levels
