Rank the following transitions in order of low to high frequencies: 3-2; 4-3; 2-1; 5-4; 5-3; 3-1; 4-2.

5-3; 4-2; 3-1; 5-4; 4-3; 3-2; 2-1 ?

Are these the quantum numbers for hydrogen?

If so, use the Rydberg relationship to compute the energy change. It is proportional to
[1/n1^2 - 1/n2^2], where n1 and n2 are the lower and upper principal quantum numbers, respectively.

The lowest frequency is the lowest energy difference, and that would be
5 -> 4

The highest frequency would be 3 -> 1, and 2 ->1 would be the second highest.

Transition [1/n1^2 - 1/n2^2]
5 -> 4........ 0.0225
5 -> 3........ 0.0400
4 -> 3........ 0.0486
3 -> 2........ 0.1389
4 -> 2........ 0.1875
2 -> 1........ 0.7500
3 -> 1 ........0.8889