Isotopes of fluorine
Although fluorine (F) has 18 known isotopes from 14F to 31F and one isomer (18mF), only one of these isotopes is stable, that is, fluorine-19; as such, it is a monoisotopic element. The longest-lived radioisotope is 18F with a half-life of 109.771 minutes. All other isotopes have half-lives under a minute, the majority under a second, making fluorine a mononuclidic element as well. The least stable isotope is 15F, whose half-life is 4.1 x 10-22 seconds, corresponding to a spectral linewidth of about 1 MeV. Only 14F has an unknown half-life.
Standard atomic mass: 18.9984032(5) u
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[edit] Fluorine-18
The nuclide 18F is the radionuclide of fluorine with the longest half-life, 109.771 minutes, allowing it to serve commercially as an important source of positrons. Its major use is for the production of the radiopharmaceutical fludeoxyglucose for positron emission tomography scanning in medicine.
[edit] Fluorine-19
Fluorine-19, the most stable isotope of fluorine. Its abundance on earth is 100%; no other isotopes of fluorine exist in significant quantities. Its binding energy is 147801 keV. Fluorine-19 is NMR-active, so it is used in fluorine-19 NMR spectroscopy.
[edit] Fluorine-20
Fluorine-20, is one of the more unstable isotopes of fluorine. It has a half-life of 11.07 seconds and undergoes beta decay, transforming into its daughter nuclide 20Ne. Its specific radioactivity is 1.885 x 109 TBq/g and has a life time of 15.87 seconds.
[edit] Fluorine-21
Fluorine-21, as with fluorine-20, is also one of the more unstable isotopes of this element. It has a half-life of 4.158 seconds. It undergoes beta decay as well which leaves behind a daughter nuclei of 21Ne. Its specific radioactivity is 4.78 x 109 TBq/g.
[edit] Table
| nuclide symbol |
Z(p) | N(n) | isotopic mass (u) |
half-life | decay mode(s)[1] | daughter isotope(s)[n 1] |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| excitation energy | |||||||||
| 14F | 9 | 5 | 14.03506(43)# | p | 13O | 2-# | |||
| 15F | 9 | 6 | 15.01801(14) | 410(60)×10−24 s [1.0(2) MeV] |
p | 14O | (1/2+) | ||
| 16F | 9 | 7 | 16.011466(9) | 11(6)×10−21 s [40(20) keV] |
p | 15O | 0- | ||
| 17F | 9 | 8 | 17.00209524(27) | 64.49(16) s | β+ | 17O | 5/2+ | ||
| 18F[n 2] | 9 | 9 | 18.0009380(6) | 109.771(20) min | β+ | 18O | 1+ | ||
| 18mF | 1121.36(15) keV | 162(7) ns | 5+ | ||||||
| 19F | 9 | 10 | 18.99840322(7) | Stable | 1/2+ | 1.0000 | |||
| 20F | 9 | 11 | 19.99998132(8) | 11.163(8) s | β− | 20Ne | 2+ | ||
| 21F | 9 | 12 | 20.9999490(19) | 4.158(20) s | β− | 21Ne | 5/2+ | ||
| 22F | 9 | 13 | 22.002999(13) | 4.23(4) s | β− (89.0%) | 22Ne | 4+,(3+) | ||
| β−, n (11.0%) | 21Ne | ||||||||
| 23F | 9 | 14 | 23.00357(9) | 2.23(14) s | β− (86.0%) | 23Ne | (3/2,5/2)+ | ||
| β−, n (14.0%) | 22Ne | ||||||||
| 24F | 9 | 15 | 24.00812(8) | 400(50) ms | β− (94.1%) | 24Ne | (1,2,3)+ | ||
| β−, n (5.9%) | 23Ne | ||||||||
| 25F | 9 | 16 | 25.01210(11) | 50(6) ms | β− (76.0%) | 25Ne | (5/2+)# | ||
| β−, n (24.0%) | 24Ne | ||||||||
| 26F | 9 | 17 | 26.01962(18) | 9.6(8) ms | β− (68.0%) | 26Ne | 1+ | ||
| β−, n (32.0%) | 25Ne | ||||||||
| 27F | 9 | 18 | 27.02676(40) | 4.9(2) ms | β− | 27Ne | 5/2+# | ||
| 28F | 9 | 19 | 28.03567(55)# | <40 ns | n | 27F | |||
| 29F | 9 | 20 | 29.04326(62)# | 2.6(3) ms | β− | 29Ne | 5/2+# | ||
| 30F | 9 | 21 | 30.05250(64)# | <260 ns | |||||
| 31F | 9 | 22 | 31.06043(64)# | 1# ms [>260 ns] | 5/2+# | ||||
[edit] Notes
- Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
- Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.
[edit] References
- Isotope masses from:
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties". Nuclear Physics A 729: 3–128. Bibcode 2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
- Isotopic compositions and standard atomic masses from:
- J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry 75 (6): 683–800. doi:10.1351/pac200375060683. http://www.iupac.org/publications/pac/75/6/0683/pdf/.
- M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051. http://iupac.org/publications/pac/78/11/2051/pdf/. Lay summary.
- Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties". Nuclear Physics A 729: 3–128. Bibcode 2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
- National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. http://www.nndc.bnl.gov/nudat2/. Retrieved September 2005.
- N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0849304859.
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