what is released when an excited electron returns to a lower energy state?\no an isotope\no a proton\no…

Brief Explanations:

When an excited electron moves from a higher - energy state to a lower - energy state, it releases energy in the form of electromagnetic radiation. An isotope is a form of an element with a different number of neutrons, a proton is a sub - atomic particle in the nucleus, and electricity is a flow of electric charge. None of these are released when an electron changes energy states.

Answer:

electromagnetic radiation