Isotopes of ruthenium

Naturally occurring ruthenium (Ru) is composed of seven stable isotopes. Additionally, 27 radioactive isotopes have been discovered. Of these radioisotopes, the most stable are ¹⁰⁶Ru with a half-life of 373.59 days, ¹⁰³Ru with a half-life of 39.26 days and ⁹⁷Ru with a half-life of 2.9 days.

Twenty-four other radioisotopes have been characterized with atomic weights ranging from 86.95 u (⁸⁷Ru) to 119.95 u (¹²⁰Ru). Most of these have half-lives that are less than five minutes, excepting ⁹⁵Ru (half-life: 1.643 hours) and ¹⁰⁵Ru (half-life: 4.44 hours).

The primary decay mode before the most abundant isotope, ¹⁰²Ru, is electron capture and the primary mode after is beta emission. The primary decay product before ¹⁰²Ru is technetium and the primary mode after is rhodium.

Standard atomic mass: 101.07(2) u

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)^[1]^{[n 1]}	daughter isotope(s)^{[n 2]}	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life	decay mode(s)^[1]^{[n 1]}	daughter isotope(s)^{[n 2]}	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
⁸⁷Ru	44	43	86.94918(64)#	50# ms [>1.5 µs]	β⁺	⁸⁷Tc	1/2-#
⁸⁸Ru	44	44	87.94026(43)#	1.3(3) s [1.2(+3-2) s]	β⁺	⁸⁸Tc	0+
⁸⁹Ru	44	45	88.93611(54)#	1.38(11) s	β⁺	⁸⁹Tc	(7/2)(+#)
⁹⁰Ru	44	46	89.92989(32)#	11.7(9) s	β⁺	⁹⁰Tc	0+
⁹¹Ru	44	47	90.92629(63)#	7.9(4) s	β⁺	⁹¹Tc	(9/2+)
^91mRu	80(300)# keV			7.6(8) s	β⁺ (>99.9%)	⁹¹Tc	(1/2-)
					IT (<.1%)	⁹¹Ru
					β⁺, p (<.1%)	⁹⁰Mo
⁹²Ru	44	48	91.92012(32)#	3.65(5) min	β⁺	⁹²Tc	0+
⁹³Ru	44	49	92.91705(9)	59.7(6) s	β⁺	⁹³Tc	(9/2)+
^93m1Ru	734.40(10) keV			10.8(3) s	β⁺ (78%)	⁹³Tc	(1/2)-
					IT (22%)	⁹³Ru
					β⁺, p (.027%)	⁹²Mo
^93m2Ru	2082.6(9) keV			2.20(17) µs			(21/2)+
⁹⁴Ru	44	50	93.911360(14)	51.8(6) min	β⁺	⁹⁴Tc	0+
^94mRu	2644.55(25) keV			71(4) µs			(8+)
⁹⁵Ru	44	51	94.910413(13)	1.643(14) h	β⁺	⁹⁵Tc	5/2+
⁹⁶Ru	44	52	95.907598(8)	Observationally Stable^{[n 3]}			0+	0.0554(14)
⁹⁷Ru	44	53	96.907555(9)	2.791(4) d	β⁺	^97mTc	5/2+
⁹⁸Ru	44	54	97.905287(7)	Observationally Stable^{[n 4]}			0+	0.0187(3)
⁹⁹Ru	44	55	98.9059393(22)	Observationally Stable^{[n 4]}			5/2+	0.1276(14)
¹⁰⁰Ru	44	56	99.9042195(22)	Observationally Stable^{[n 4]}			0+	0.1260(7)
¹⁰¹Ru^{[n 5]}	44	57	100.9055821(22)	Observationally Stable^{[n 4]}			5/2+	0.1706(2)
^101mRu	527.56(10) keV			17.5(4) µs			11/2-
¹⁰²Ru^{[n 5]}	44	58	101.9043493(22)	Observationally Stable^{[n 4]}			0+	0.3155(14)
¹⁰³Ru^{[n 5]}	44	59	102.9063238(22)	39.26(2) d	β^-	¹⁰³Rh	3/2+
^103mRu	238.2(7) keV			1.69(7) ms	IT	¹⁰³Ru	11/2-
¹⁰⁴Ru^{[n 5]}	44	60	103.905433(3)	Observationally Stable^{[n 6]}			0+	0.1862(27)
¹⁰⁵Ru^{[n 5]}	44	61	104.907753(3)	4.44(2) h	β^-	¹⁰⁵Rh	3/2+
¹⁰⁶Ru^{[n 5]}	44	62	105.907329(8)	373.59(15) d	β^-	¹⁰⁶Rh	0+
¹⁰⁷Ru	44	63	106.90991(13)	3.75(5) min	β^-	¹⁰⁷Rh	(5/2)+
¹⁰⁸Ru	44	64	107.91017(12)	4.55(5) min	β^-	¹⁰⁸Rh	0+
¹⁰⁹Ru	44	65	108.91320(7)	34.5(10) s	β^-	¹⁰⁹Rh	(5/2+)#
¹¹⁰Ru	44	66	109.91414(6)	11.6(6) s	β^-	¹¹⁰Rh	0+
¹¹¹Ru	44	67	110.91770(8)	2.12(7) s	β^-	¹¹¹Rh	(5/2+)
¹¹²Ru	44	68	111.91897(8)	1.75(7) s	β^-	¹¹²Rh	0+
¹¹³Ru	44	69	112.92249(8)	0.80(5) s	β^-	¹¹³Rh	(5/2+)
^113mRu	130(18) keV			510(30) ms			(11/2-)
¹¹⁴Ru	44	70	113.92428(25)#	0.53(6) s	β^- (>99.9%)	¹¹⁴Rh	0+
¹¹⁴Ru	44	70	113.92428(25)#	0.53(6) s	β^-, n (<.1%)	¹¹³Rh	0+
¹¹⁵Ru	44	71	114.92869(14)	740(80) ms	β^- (>99.9%)	¹¹⁵Rh
¹¹⁵Ru	44	71	114.92869(14)	740(80) ms	β^-, n (<..1%)	¹¹⁴Rh
¹¹⁶Ru	44	72	115.93081(75)#	400# ms [>300 ns]	β^-	¹¹⁶Rh	0+
¹¹⁷Ru	44	73	116.93558(75)#	300# ms [>300 ns]	β^-	¹¹⁷Rh
¹¹⁸Ru	44	74	117.93782(86)#	200# ms [>300 ns]	β^-	¹¹⁸Rh	0+
¹¹⁹Ru	44	75	118.94284(75)#	170# ms [>300 ns]
¹²⁰Ru	44	76	119.94531(86)#	80# ms [>300 ns]			0+

^ Abbreviations:
IT: Isomeric transition
^ Bold for stable isotopes
^ Believed to undergo β⁺β⁺ decay to ⁹⁶Mo with a half-life over 67×10¹⁵ years
^ ^a ^b ^c ^d ^e Theoretically capable of spontaneous fission
^ ^a ^b ^c ^d ^e ^f Fission product
^ Believed to undergo β^-β^- decay to ¹⁰⁴Pd

Notes

Geologically exceptional samples are known in which the isotopic composition lies outside the reported range. The uncertainty in the atomic mass may exceed the stated value for such specimens.
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

^ 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. 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.

Isotopes of technetium	Isotopes of ruthenium	Isotopes of rhodium
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