Technetium also has numerous nuclear isomers, which are isotopes with one or more excited nucleons. Technetium-97m (97mTc; "m" stands for metastability) is the most stable, with a half-life of 91 days and excitation energy 0.0965 MeV. This is followed by technetium-95m (61 days, 0.03 MeV), and technetium-99m (6.01 hours, 0.142 MeV).
Technetium also has numerous nuclear isomers, which are isotopes with one or more excited nucleons. Technetium-97m (97mTc; "m" stands for metastability) is the most stable, with a half-life of 91 days and excitation energy 0.0965 MeV. This is followed by technetium-95m (61 days, 0.03 MeV), and technetium-99m (6.01 hours, 0.142 MeV).