Isotopes of tungsten

Naturally occurring tungsten (atomic symbol W) consists of four stable isotopes (¹⁸²W, ¹⁸³W, ¹⁸⁴W, and ¹⁸⁶W) and one isotope, ¹⁸⁰W, with an extremely long half-life of 1.8 ± 0.2 Ea (10¹⁸ years). On average, two alpha decays of ¹⁸⁰W occur per gram of natural tungsten per year.

33 artificial radioisotopes of tungsten have been characterized with mass numbers ranging from 157 to 194, the most stable of which are ¹⁸¹W with a half-life of 121.2 days, ¹⁸⁵W with a half-life of 75.1 days, ¹⁸⁸W with a half-life of 69.4 days and ¹⁷⁸W with a half-life of 21.6 days. All of the remaining radioactive isotopes have half-lives of less than 24 hours, and most of these have half-lives that are less than 8 minutes. Tungsten also has 11 meta states with mass numbers of 158, 179, with 3, 180, with 2, 183, 185, 186, with 2, and 190, the most stable being ^179m1W (t_½ 6.4 minutes).

Standard atomic mass: 183.84(1) u

Table

1. ↑ Bold for isotopes with half-lives longer than the age of the universe (nearly stable)
2. ↑ Abbreviations:
   EC: Electron capture
   IT: Isomeric transition
3. ↑ Bold for stable isotopes, bold italics for nearly-stable isotopes (half-life longer than the age of the universe)
4. ↑ Primordial radionuclide
5. ↑ Believed to undergo α decay to ¹⁷⁸Hf with a half-life over 1.70×10²⁰ years
6. ↑ Believed to undergo α decay to ¹⁷⁹Hf with a half-life over 80×10¹⁸ years
7. ↑ Believed to undergo α decay to ¹⁸⁰Hf with a half-life over 180×10¹⁸ years
8. ↑ Believed to undergo α decay to ¹⁸²Hf with a half-life over 4.1×10¹⁸ years

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.

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. 
• 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. 
  • 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. 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. 
  • National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. 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 978-0-8493-0485-9.