 The electrons around the nucleus rapidly adjust themselves to the lowered charge without leaving their shell, and shortly thereafter the vacancy in the "K" shell left by the nuclear-captured electron is filled by an electron from a higher shell.The difference in energy is released by emitting Auger electrons of 5.19 keV, with a probability of about 60%, K-alpha-1 X-rays with energy of 5.89875 keV and a probability about 16.2%, K-alpha-2 X-rays with energy of 5.88765 keV and a probability of about 8.2%, or K-beta X-rays with nominal energy of 6.49045 keV and a probability about 2.85%.The energies of the K-alpha-1 and -2 X-rays are so similar that they are often specified as mono-energetic radiation with 5.9 keV photon energy.