Question

Which quantum numbers are involved in the transition that requires the least energy?

Based on the drawing, put the following in order of decreasing wavelength of the light absorbed or emitted during the transition.

http://tinypic.com/view.php?pic=658w8k&s=5#.VDhFUSldV8s

Answer 1

Based on that drawing transition n=1 to n=2 is the smallest in energy, so it would have the longest wavelength of emission. But that's incorrect in reality, n=1 to n=2 transitions are the most energetic (in terms of "jumping" from consecutive numbers), so it should have the shortest wavelength.