An electron in the L shell “sees” an effective charge Z=13−1=12, because one electron in the K shell shields the nuclear charge. (Recall, two electrons are not in the K shell because the oth...An electron in the L shell “sees” an effective charge Z=13−1=12, because one electron in the K shell shields the nuclear charge. (Recall, two electrons are not in the K shell because the other electron state is vacant.) The frequency of the emitted photon can be estimated from the energy difference between the L and K shells.
