Isotopes of fluorine

Of the unstable nuclides of fluorine, has the longest half-life, . It decays to via β+ decay. For this reason is a commercially important source of positrons. Its major value is in the production of the radiopharmaceutical fludeoxyglucose, used in positron emission tomography in medicine. Fluorine-18 is the second lightest unstable nuclide (after beryllium-8, with 4 protons and 4 neutrons) with equal numbers of protons and neutrons and lightest such with an odd atomic number, having 9 of each. (See also the parity discussion of nuclide stability.) ==Fluorine-19==

Fluorine-19 is the only stable isotope of fluorine. Its abundance is ; no other isotopes of fluorine exist in significant quantities. Its binding energy is . Fluorine-19 is NMR-active with a spin of 1/2+, so it is used in fluorine-19 NMR spectroscopy. ==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 particle-bound fluorine radioisotope nuclear ground states. 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. == See also ==