1. The problem statement, all variables and given/known data Calculate the wavelength of light needed to excite a Li2+ ion from the 4s to the 5d orbital. Report your answer with 3 significant figures. 2. Relevant equations E=hc/lambda lambda=hc/E 3. The attempt at a solution I think that the above equations are supposed to be used to figure out the wavelength. However, I need to figure out the energy (E) first. I don't know how to do this. Can this be calculated just thinking of the orbitals as excited states??