Isotopes of fluorine

Fluorine (₉F) has 19 known isotopes ranging from to and two isomers ( and ). Only fluorine-19 is stable and naturally occurring in more than trace quantities; therefore, fluorine is a monoisotopic and a mononuclidic element.

The longest-lived radioisotope is with a half-life of 109.734 minutes, followed by with 64.37 seconds. These unstable isotopes participate in the CNO cycle within stars. All other fluorine isotopes have half-lives of less than 12 seconds, and most of those less than 1/2 second.

List of isotopes

|-id=Fluorine-13 | | style="text-align:right" | 9 | style="text-align:right" | 4 | # | | p ? | | 1/2+# | |-id=Fluorine-14 | | style="text-align:right" | 9 | style="text-align:right" | 5 | | <br/>[] | p ? | | 2− | |-id=Fluorine-15 | | style="text-align:right" | 9 | style="text-align:right" | 6 | | <br/>[] | p | | 1/2+ | |-id=Fluorine-16 | | style="text-align:right" | 9 | style="text-align:right" | 7 | | <br/>[] | p | | 0− | |-id=Fluorine-17 | | style="text-align:right" | 9 | style="text-align:right" | 8 | | | β⁺ | | 5/2+ | |- | | style="text-align:right" | 9 | style="text-align:right" | 9 | | | β⁺ | | 1+ | Trace |-id=Fluorine-18m | style="text-indent:1em" | | colspan="3" style="text-indent:2em" | | | IT | | 5+ | |- | | style="text-align:right" | 9 | style="text-align:right" | 10 | | colspan=3 align=center|Stable | 1/2+ | 1 |- | | style="text-align:right" | 9 | style="text-align:right" | 11 | | | β^− | | 2+ | |- | | style="text-align:right" | 9 | style="text-align:right" | 12 | | | β^− | | 5/2+ | |-id=Fluorine-22 | rowspan=2| | rowspan=2 style="text-align:right" | 9 | rowspan=2 style="text-align:right" | 13 | rowspan=2| | rowspan=2| | β^− (> ) | | rowspan=2|(4+) | rowspan=2| |- | β^−n (< ) | |-id=Fluorine-23 | rowspan=2| | rowspan=2 style="text-align:right" | 9 | rowspan=2 style="text-align:right" | 14 | rowspan=2| | rowspan=2| | β^− (> ) | | rowspan=2|5/2+ | rowspan=2| |- | β^−n (< ) | |-id=Fluorine-24 | rowspan=2| | rowspan=2 style="text-align:right" | 9 | rowspan=2 style="text-align:right" | 15 | rowspan=2| | rowspan=2| | β^− (> ) | | rowspan=2|3+ | rowspan=2| |- | β^−n (< ) | |-id=Fluorine-25 | rowspan=3| | rowspan=3 style="text-align:right" | 9 | rowspan=3 style="text-align:right" | 16 | rowspan=3| | rowspan=3| | β^− () | | rowspan=3|(5/2+) | rowspan=3| |- | β^−n () | |- | β^−2n ? | ? |-id=Fluorine-26 | rowspan=3| | rowspan=3 style="text-align:right" | 9 | rowspan=3 style="text-align:right" | 17 | rowspan=3| | rowspan=3| | β^− () | | rowspan=3|1+ | rowspan=3| |- | β^−n () | |- | β^−2n ? | ? |-id=Fluorine-26m | rowspan=3 style="text-indent:1em" | | rowspan=3 colspan="3" style="text-indent:2em" | | rowspan=3 | | IT () | | rowspan=3|(4+) | rowspan=3| |- | β^−n () | |- | β^− ? | ? |-id=Fluorine-27 | rowspan=3| | rowspan=3 style="text-align:right" | 9 | rowspan=3 style="text-align:right" | 18 | rowspan=3| | rowspan=3| | β^−n () | | rowspan=3|5/2+# | rowspan=3| |- | β^− () | |- | β^−2n ? | ? |-id=Fluorine-28 | | style="text-align:right" | 9 | style="text-align:right" | 19 | | | n | | (4−) | |-id=Fluorine-29 | rowspan=3| | rowspan=3 style="text-align:right" | 9 | rowspan=3 style="text-align:right" | 20 | rowspan=3| | rowspan=3| | β^−n () | | rowspan=3|(5/2+) | rowspan=3| |- | β^− () | |- | β^−2n ? | ? |-id=Fluorine-30 | | style="text-align:right" | 9 | style="text-align:right" | 21 | # | | n | | | |-id=Fluorine-31 | rowspan=3| | rowspan=3 style="text-align:right" | 9 | rowspan=3 style="text-align:right" | 22 | rowspan=3|# | rowspan=3|# [> ] | β^− ? | ? | rowspan=3|5/2+# | rowspan=3| |- | β^−n ? | ? |- | β^−2n ? | ? |-

Fluorine-18

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

Daughter products other than fluorine

• Isotopes of neon
• Isotopes of oxygen

References

Sources