Astronomy help: Balmer Lines?

[Leilani0541]

I am doing a take-home lab for my astronomy class on Spectral Classification and Balmer Lines. I'm completely lost and really could use some help!1) Why do hydrogen Balmer lines get closer and closer together at shorter wavelengths?2) Why might we expect hydrogen Balmer lines to be weak in very hot stars?3) If we do not see lines of a specific element in a star's spectrum, may we conclude that the element is ablsent? Why?

[AdamF]

1. The energy levels in hydrogen get closer together the closer you get to the ionization energy. This makes the photons have energies that are closer to each other, which results in having wavelengths closer to each other.2. Very hot stars ionize their hydrogen, so there is not much atomic hydrogen to form the Balmer lines3. No, the lines may not be showing up because the material is the wrong temperature ( too hot or too cold ).