Isotopes of ruthenium

Isotopes of ruthenium (44Ru)
Main isotopes[1] Decay
abun­dance half-life (t1/2) mode pro­duct
96Ru 5.54% stable
97Ru synth 2.9 d ε 97Tc
γ –
98Ru 1.87% stable
99Ru 12.8% stable
100Ru 12.6% stable
101Ru 17.1% stable
102Ru 31.6% stable
103Ru synth 39.26 d β− 103Rh
γ –
104Ru 18.6% stable
106Ru synth 373.59 d β− 106Rh
Standard atomic weight Ar°(Ru)

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)
Excitation energy[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+
β−, n (<.1%) 113Rh
115Ru 44 71 114.92869(14) 740(80) ms β− (>99.9%) 115Rh
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+
This table header & footer:
  1. ^ mRu – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ a b c # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ^ Modes of decay:
    IT: Isomeric transition
    n: Neutron emission
    p: Proton emission
  6. ^ Bold symbol as daughter – Daughter product is stable.
  7. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  8. ^ Believed to undergo β+β+ decay to 96Mo with a half-life over 6.7×1016 years
  9. ^ a b c d e f Fission product
  10. ^ Believed to undergo β−β− decay to 104Pd
  • 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]
Ruthenium-96

References

  1. ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ^ "Standard Atomic Weights: Ruthenium". CIAAW. 1983.
  3. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  4. ^ Ronneau, C., Cara, J., & Rimski-Korsakov, A. (1995). Oxidation-enhanced emission of ruthenium from nuclear fuel. Journal of Environmental Radioactivity, 26(1), 63-70.
  5. ^ a b Backman, U., Lipponen, M., Auvinen, A., Jokiniemi, J., & Zilliacus, R. (2004). Ruthenium behaviour in severe nuclear accident conditions. Final report (No. NKS–100). Nordisk Kernesikkerhedsforskning.
  6. ^ Beuzet, E., Lamy, J. S., Perron, H., Simoni, E., & Ducros, G. (2012). Ruthenium release modelling in air and steam atmospheres under severe accident conditions using the MAAP4 code[dead link]. Nuclear Engineering and Design, 246, 157-162.
  7. ^ [1] Detection of ruthenium 106 in France and in Europe, IRSN France (9 Nov 2017)