This excited state of Te-123 produced is not the metastable nuclear isomer Te-123m ( the decay of I-123 does not involve enough energy to produce Te-123m ), but rather is a lower-energy nuclear isomer of Te-123 that immediately gamma decays to ground state Te-123 at the energies noted, or else ( 13 % of the time ) decays by internal conversion electron emission ( 127 keV ), followed by an average of 11 Auger electrons emitted at very low energies ( 50-500 eV ).
