Calculate the wavelength and frequency of the radiation emitted by the electronic transition from the 10th to the 9th excited state of hydrogen.

Using the formula in theMore Precisely4.2, the energy in the  eleventh level is E11= 13.59843(1-1/112) eV = 13.48604628 eV, E10= 13.59843(1-1/102) eV = 13.4624457 eV.T he difference between these two levels is 0.02360058 eV. Converting to Joules (see #3) we have 3.781x10-21J. Using E = hf, the frequency of this wave can be calculated – we find f = 5.707x1012Hz.In wavelength this is 52,534 nm or 52.5 microns which is in the infrared.