what happens in gamma decay
Gamma decay occurs when the nucleus undergoes an energy state change without actually changing the number or ratio of nucleons. . Technetium-99m (99mTc) is an example of such an atom. Its nucleus is the isomer of Technetium-99 (99Tc), and as an isomer, Technetium-99m rests at a higher energy state than the ground state Technetium-99.