In the hydrogen atom, with Z = 1, the energy of the emitted photon can be found using:
E = (13.6 eV) [1/n22 - 1/n32]
= -1.13 eV
= -1.13 x 1.6 x 10-19 J = 1.808 x 10-19 J
E = hν
1.808 x 10-19 J = (6.626 x 10¯34 J s) (ν)
ν = 0.273 x 1015 s-1