The following is a summary of four energy-level transitions for an electron in a hydrogen atom: I - ni = 1 nf = 5 II - ni = 4 nf = 3 III - ni = 2 nf = 5 IV - ni = 8 nf = 3

A) For which of these transition(s) does the atom gain energy?

B) For which transition does the atom gain the most energy?

C) Which transition emits the photon with the longest wavelength?