Describe the energy levels of an atom and how an electron moves between them. (be sure to
describe how the electron absorbs and emits energy when it does so.)

answer quickly

Energy levels : It refers to the shells of definite energy in which electron revolves around the nucleus .

Explanation:

As we know, that atom consist of small dense mass that is nucleus and around it the shells of definite energy are present .

We also know ,atom consist of sub atomic particles that is :

ElectronprotonNeutronIn shells the electrons are present and are not stationary (they are revolving ).The electron never absorbs or releases energy by itself .The electron in shells have definite energy that is the reason the shells are referred as energy levels .But, when we supply energy to electron which is more than the energy of the shell then it gets excited to higher energy level (depending upon magnitude of energy supplied ).The higher energy level is regarded as excited state .The excited states are always unstable .So, electron revolves there for short span of time but ultimately it returns to its own shell and by doing so it release the energy absorbed by it .The energy released is actually a difference in the energy of ground state (original state ) and energy of excited state .ΔE=E₂-E₁