Isotopes of fluorine

Isotopes of fluorine
Fluorine (9F) has 18 known isotopes ranging from to (with the exception of ) and two isomers (and ). Only fluorine-19 is stable and naturally occurring in more than trace quantities; therefore, fluorine is a monoisotopic and mononuclidic element.
The longest-lived radioisotope is ; it has a half-life of . All other fluorine isotopes have half-lives of less than a minute, and most of those less than a second. The least stable known isotope is , whose half-life is , corresponding to a resonance width of .
List of isotopes
|-
|
| style="text-align:right" | 9
| style="text-align:right" | 4
| #
|
| p ?
| ?
| 1/2+#
|
|
|-
|
| style="text-align:right" | 9
| style="text-align:right" | 5
|
| []
| p ?
| ?
| 2−
|
|
|-
|
| style="text-align:right" | 9
| style="text-align:right" | 6
|
| []
| p
|
| 1/2+
|
|
|-
|
| style="text-align:right" | 9
| style="text-align:right" | 7
|
| []
| p
|
| 0−
|
|
|-
|
| 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
|
|-
| 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+
| colspan=2 style="text-align:center"|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+
|
|
|-
| 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|
| rowspan=2|
|-
| β−n (< )
|
|-
| 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|
| rowspan=2|
|-
| β−n (< )
|
|-
| 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|
| rowspan=2|
|-
| β−n (< )
|
|-
| 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|
| rowspan=3|
|-
| β−n
|
|-
| β−2n ?
| ?
|-
| 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|
| rowspan=3|
|-
| β−n
|
|-
| β−2n ?
| ?
|-
| rowspan=3 style="text-indent:1em" |
| rowspan=3 colspan="3" style="text-indent:2em" |
| rowspan=3 |
| IT
|
| rowspan=3|(4+)
| rowspan=3|
| rowspan=3|
|-
| β−n
|
|-
| β− ?
| ?
|-
| 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|
| rowspan=3|
|-
| β−
|
|-
| β−2n ?
| ?
|-
|
| style="text-align:right" | 9
| style="text-align:right" | 19
|
|
| n
|
| (4−)
|
|
|-
| 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|
| rowspan=3|
|-
| β−
|
|-
| β−2n ?
| ?
|-
| 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|
| 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 lightest unstable nuclide with equal odd numbers of protons and neutrons, having 9 of each. (See also the "magic numbers" 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.
Fluorine-20
Fluorine-20 is an unstable isotope of fluorine. It has a half-life of and decays via beta decay to the stable nuclide . Its specific radioactivity is and has a mean lifetime of .
Fluorine-21
Fluorine-21, as with fluorine-20, is also an unstable isotope of fluorine. It 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
Sources
Fluorine
Fluorine