Question

If a Li 2+ ion, initially in the 2nd excited state absorbs a photon of light with a fequency of 2.82 X 10^6 GHz, what will be the final energy level for this electron? Show all stepts to get final energy level.


i have no clue what this question is even asking :[?

Answer 1

I thought I answered this but I don't see my post. The trick is to use the Rydberg formula for the energy levels of Li2+. The Rydberg constant is nine times the value for hydrogen. The frequency of the absorbed light tells you the difference of the energy levels. You get the initial energy level by using n=2 in the Rydberg formula, which says that the energy level is -(constant)/n^2

You will find a full explanation at
http://en.wikipedia.org/wiki/Rydberg_formula