The ionization energy of a certain element is 412 ~kJ ~mol^ -1 ....

The ionization energy of a certain element is $412 \mathrm{~kJ} \mathrm{~mol}^{-1}$. When the atoms of this element are in the first excited state, however, the ionization energy is only $126 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The region of the electromagnetic spectrum in which the wavelength of light emitted in a transition from the first excited state to the ground state is