Isotopes of ruthenium

Isotopes of ruthenium (₄₄Ru)
γ	–
γ	–
Standard atomic weight Ar°(Ru)
	101.07±0.02; 101.07±0.02 (abridged);
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Naturally occurring ruthenium (₄₄Ru) is composed of seven stable isotopes (of which two may in the future be found radioactive). 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, except ⁹⁴Ru (half-life: 51.8 minutes), 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 product after is rhodium.

Because of the very high volatility of ruthenium tetroxide (RuO
₄) ruthenium radioactive isotopes with their relative short half-life are considered as the second most hazardous gaseous isotopes after iodine-131 in case of release by a nuclear accident.^[4]^[5]^[6] The two most important isotopes of ruthenium in case of nuclear accident are these with the longest half-life: ¹⁰³Ru (39.26 days) and ¹⁰⁶Ru (373.59 days).^[5]

List of isotopes

Nuclide ^{[n 1]}	Z	N	Isotopic mass (Da) ^{[n 2]}^{[n 3]}	Half-life ^{[n 4]}	Decay mode ^{[n 5]}	Daughter isotope ^{[n 6]}	Spin and parity ^{[n 7]}^{[n 4]}	Natural abundance (mole fraction)
Nuclide ^{[n 1]}	Excitation energy^{[n 4]}			Half-life ^{[n 4]}	Decay mode ^{[n 5]}	Daughter isotope ^{[n 6]}	Spin and parity ^{[n 7]}^{[n 4]}	Normal proportion	Range of variation
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 8]}			0+	0.0554(14)
⁹⁷Ru	44	53	96.907555(9)	2.791(4) d	β⁺	^97mTc	5/2+
⁹⁸Ru	44	54	97.905287(7)	Stable			0+	0.0187(3)
⁹⁹Ru	44	55	98.9059393(22)	Stable			5/2+	0.1276(14)
¹⁰⁰Ru	44	56	99.9042195(22)	Stable			0+	0.1260(7)
¹⁰¹Ru^{[n 9]}	44	57	100.9055821(22)	Stable			5/2+	0.1706(2)
^101mRu	527.56(10) keV			17.5(4) μs			11/2−
¹⁰²Ru^{[n 9]}	44	58	101.9043493(22)	Stable			0+	0.3155(14)
¹⁰³Ru^{[n 9]}	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 9]}	44	60	103.905433(3)	Observationally Stable^{[n 10]}			0+	0.1862(27)
¹⁰⁵Ru^{[n 9]}	44	61	104.907753(3)	4.44(2) h	β⁻	¹⁰⁵Rh	3/2+
¹⁰⁶Ru^{[n 9]}	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+
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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.^{[citation needed]}
In September 2017 an estimated amount of 100 to 300 TBq (0.3 to 1 g) of ¹⁰⁶Ru was released in Russia, probably in the Ural region. It was, after ruling out release from a reentering satellite, concluded that the source is to be found either in nuclear fuel cycle facilities or radioactive source production. In France levels up to 0.036mBq/m³ of air were measured. It is estimated that over distances of the order of a few tens of kilometres around the location of the release levels may exceed the limits for non-dairy foodstuffs.^[7]

References

Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (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:
- de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
- Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
"News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (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.x database". Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.

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