Why does the line spectrum of hydrogen include light of several different wavelengths...?

Question

even though a hydrogen atom only has one electron?

Answer 1

This is a very good question.

The electron can be excited into a multitude of excited states as well as emitting to a variety of lower energy states. The important thing to realize is that hydrogen has many electronic states that are unoccupied. When the electron is excited, it can go into any of those energy levels as well as getting completely ejected from the atom creating a free electron and a positive hydrogen ion.

Specifically, the three lines that are observed in the visible hydrogen spectrum are:
n=3 -> n=2;
n=4 -> n=2, and
n=5 -> n=2 transitions.

Answer 2

Well, I think it may have something to do with the isotopes of hydrogen.

Perhaps you can type "isotopes" in your search engine, and that may help further in answering your question.

Good luck!