Does this star contain hydrogen? Does this star contain He+? Justify your answer with diagrams and calculations. If I find the wavelengths of Hydrogen, can I go to the graph and check if there's any intensity at these wavelengths? Do all of the wavelengths have to exist for hydrogen to be present? As for He+, I have no idea how to do that. Any suggestions as to what kind of diagrams I might need and calculations? Oh, and how many energy levels do I need to go up to? Is the max for Hydrogen n=6? What about Helium?