has a half-life of . It undergoes beta decay as well, decaying to , which is a stable nuclide. Its specific activity is . Isomers Only two nuclear isomers (long-lived excited nuclear states), fluorine-18m and fluorine-26m, have been characterized. The half-life of before it undergoes isomeric transition is . This is less than the decay half-life of any of the fluorine radioisotope nuclear ground states except for mass numbers 14–16, 28, and 31. The half-life of is ; it decays mainly to its ground state of or (rarely, via beta-minus decay) to one of high excited states of with delayed neutron emission. External links Information on Fluorine-21 from Wolframalpha.com Information on Fluorine-20 from Wolframalpha.com References Fluorine Fluorine