An electron in a hydrogen atom relaxes to the n= 4 level, emitting light of 138 THz.

What is the value of n for the level in which the electron originated?

2 answers

a. figure energy for the photon, for the given frequency. E=hf

b. then, E= constant(1/n^2-1/16)
figure n

I can check your work if necessary.
3.6912*10^10