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 product 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)
excitation energy
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) Stable[n 4] 0+ 0.0187(3)
99Ru 44 55 98.9059393(22) Stable[n 4] 5/2+ 0.1276(14)
100Ru 44 56 99.9042195(22) Stable[n 4] 0+ 0.1260(7)
101Ru[n 5] 44 57 100.9055821(22) 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) 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+
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+
  1. Abbreviations:
    IT: Isomeric transition
  2. Bold for stable isotopes
  3. Believed to undergo β+β+ decay to 96Mo with a half-life over 6.7×1016 years
  4. 4.0 4.1 4.2 4.3 4.4 Theoretically capable of spontaneous fission
  5. 5.0 5.1 5.2 5.3 5.4 5.5 Fission product
  6. Believed to undergo ββ decay to 104Pd

Notes

References

  1. http://www.nucleonica.net/unc.aspx
Isotopes of technetium Isotopes of ruthenium Isotopes of rhodium
Table of nuclides