Isotopes of lutetium

Naturally occurring radioactive isotopes have half-lives that are less than 9 days, and the majority of these have half lives that are less than a half an hour. This element also has 18 meta states, with the most stable being Lu-177m (t_½ 160.4 days), Lu-174m (t_½ 142 days) and Lu-178m (t_½ 23.1 minutes).