Isotopes of rhenium

Naturally occurring rhenium (Re) is 37.4% ¹⁸⁵Re, which is stable, and 62.6% ¹⁸⁷Re, which is unstable but has a very long half-life (41.2×10⁹ years). Among elements with a known stable isotope, only indium and tellurium similarly occur with a stable isotope in lower abundance than the long-lived radioactive isotope.

There are 33 other unstable isotopes recognized, the longest-lived of which are ¹⁸³Re with a half-life of 70 days, ¹⁸⁴Re with a half-life of 38 days, ¹⁸⁶Re with a half-life of 3.7186 days, ¹⁸²Re with a half-life of 64.0 hours, and ¹⁸⁹Re with a half-life of 24.3 hours. There are also numerous isomers, the longest-lived of which are ^186mRe with a half-life of 200,000 years and ^184mRe with a half-life of 169 days. All others have half-lives less than a day.

Standard atomic mass: 186.207(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. ↑ Believed to undergo α decay to ¹⁸¹Ta
5. ↑ primordial radionuclide
6. ↑ Used in rhenium-osmium dating
7. ↑ Can undergo Bound-state β^- decay with a half-life of 33 years when fully ionized

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

1. ↑ http://www.nucleonica.net/unc.aspx

• 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.