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.

Relative atomic mass: 186.207(1).

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life[n 1]	decay mode(s)[1][n 2]	daughter isotope(s)[n 3]	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
	excitation energy
^160Re	75	85	159.98212(43)#	860(120) µs [0.82(+15−9) ms]	p (91%)	^159W	(2−)
					α (9%)	^156Ta
^161Re	75	86	160.97759(22)	0.37(4) ms	p	^160W	1/2+
^161mRe	123.8(13) keV			15.6(9) ms	α	^157Ta	11/2−
^162Re	75	87	161.97600(22)#	107(13) ms	α (94%)	^158Ta	(2−)
					β^+ (6%)	^162W
^162mRe	173(10) keV			77(9) ms	α (91%)	^158Ta	(9+)
					β^+ (9%)	^162W
^163Re	75	88	162.972081(21)	390(70) ms	β^+ (68%)	^163W	(1/2+)
					α (32%)	^159Ta
^163mRe	115(4) keV			214(5) ms	α (66%)	^159Ta	(11/2−)
					β^+ (34%)	^163W
^164Re	75	89	163.97032(17)#	0.53(23) s	α (58%)	^160Ta	high
					β^+ (42%)	^164W
^164mRe	120(120)# keV			530(230) ms			(2#)−
^165Re	75	90	164.967089(30)	1# s	β^+	^165W	1/2+#
					α	^161Ta
^165mRe	47(26) keV			2.1(3) s	β^+ (87%)	^165W	11/2−#
					α (13%)	^161Ta
^166Re	75	91	165.96581(9)#	2# s	β^+	^166W	2−#
					α	^162Ta
^167Re	75	92	166.96260(6)#	3.4(4) s	α	^163Ta	9/2−#
					β^+	^167W
^167mRe	130(40)# keV			5.9(3) s	β^+ (99.3%)	^167W	1/2+#
					α (.7%)	^163Ta
^168Re	75	93	167.96157(3)	4.4(1) s	β^+ (99.99%)	^168W	(5+,6+,7+)
					α (.005%)	^164Ta
^168mRe	non-exist			6.6(15) s
^169Re	75	94	168.95879(3)	8.1(5) s	β^+ (99.99%)	^169W	9/2−#
					α (.005%)	^165Ta
^169mRe	145(29) keV			15.1(15) s	β^+ (99.8%)	^169W	1/2+#
					α (.2%)	^164Ta
^170Re	75	95	169.958220(28)	9.2(2) s	β^+ (99.99%)	^170W	(5+)
					α (.01%)	^166Ta
^171Re	75	96	170.95572(3)	15.2(4) s	β^+	^171W	(9/2−)
^172Re	75	97	171.95542(6)	15(3) s	β^+	^172W	(5)
^172mRe	0(100)# keV			55(5) s	β^+	^172W	(2)
^173Re	75	98	172.95324(3)	1.98(26) min	β^+	^173W	(5/2−)
^174Re	75	99	173.95312(3)	2.40(4) min	β^+	^174W
^175Re	75	100	174.95138(3)	5.89(5) min	β^+	^175W	(5/2−)
^176Re	75	101	175.95162(3)	5.3(3) min	β^+	^176W	3+
^177Re	75	102	176.95033(3)	14(1) min	β^+	^177W	5/2−
^177mRe	84.71(10) keV			50(10) µs			5/2+
^178Re	75	103	177.95099(3)	13.2(2) min	β^+	^178W	(3+)
^179Re	75	104	178.949988(26)	19.5(1) min	β^+	^179W	(5/2)+
^179m1Re	65.39(9) keV			95(25) µs			(5/2−)
^179m2Re	1684.59(14)+Y keV			>0.4 µs			(23/2+)
^180Re	75	105	179.950789(23)	2.44(6) min	β^+	^180W	(1)−
^181Re	75	106	180.950068(14)	19.9(7) h	β^+	^181W	5/2+
^182Re	75	107	181.95121(11)	64.0(5) h	β^+	^182W	7+
^182m1Re	60(100) keV			12.7(2) h	β^+	^182W	2+
^182m2Re	235.736(10)+X keV			585(21) ns			2−
^182m3Re	461.3(1)+X keV			0.78(9) µs			(4−)
^183Re	75	108	182.950820(9)	70.0(14) d	EC	^183W	5/2+
^183mRe	1907.6(3) keV			1.04(4) ms	IT	^183Re	(25/2+)
^184Re	75	109	183.952521(5)	38.0(5) d	β^+	^184W	3(−)
^184mRe	188.01(4) keV			169(8) d	IT (75.4%)	^184Re	8(+)
					β^+ (24.6%)	^184W
^185Re	75	110	184.9529550(13)	Observationally Stable[n 4]			5/2+	0.3740(2)
^185mRe	2124(2) keV			123(23) ns			(21/2)
^186Re	75	111	185.9549861(13)	3.7186(5) d	β^− (93.1%)	^186Os	1−
					EC (6.9%)	^186W
^186mRe	149(7) keV			2.0(5)×10^5 y	IT (90%)	^186Re	(8+)
					β^− (10%)	^186Os
^187Re[n 5][n 6]	75	112	186.9557531(15)	41.2(2)×10^9 y[n 7]	β^− (99.99%)	^187Os	5/2+	0.6260(2)
					α (10^−4%)	^183Ta
^188Re	75	113	187.9581144(15)	17.0040(22) h	β^−	^188Os	1−
^188mRe	172.069(9) keV			18.59(4) min	IT	^188Re	(6)−
^189Re	75	114	188.959229(9)	24.3(4) h	β^−	^189Os	5/2+
^190Re	75	115	189.96182(16)	3.1(3) min	β^−	^190Os	(2)−
^190mRe	210(50) keV			3.2(2) h	β^− (54.4%)	^190Os	(6−)
					IT (45.6%)	^190Re
^191Re	75	116	190.963125(11)	9.8(5) min	β^−	^191Os	(3/2+,1/2+)
^192Re	75	117	191.96596(21)#	16(1) s	β^−	^192Os
^193Re	75	118	192.96747(21)#	30# s [>300 ns]			5/2+#
^194Re	75	119	193.97042(32)#	2# s [>300 ns]

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. "Universal Nuclide Chart". nucleonica. (registration required (help)).

• Isotope masses from:
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). 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; 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; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). 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.