| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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 masses ranging from 86.95 Da (87Ru) to 119.95 Da (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 isotopes with relatively short half-life are considered the next most hazardous airborne isotopes, after iodine-131, in case of release by a nuclear accident. [4] [5] [6] The two most important isotopes of ruthenium so released are those with the longest half-life: 103Ru (39.26 days) and 106Ru (373.59 days). [5]
Nuclide [n 1] | Z | N | Isotopic mass (Da) [7] [n 2] [n 3] | Half-life [1] [n 4] | Decay mode [1] [n 5] | Daughter isotope [n 6] | Spin and parity [1] [n 7] [n 4] | Natural abundance (mole fraction) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy [n 4] | Normal proportion [1] | Range of variation | |||||||||||||||||
85Ru | 44 | 41 | 84.96712(54)# | 1# ms [> 400 ns] | 3/2−# | ||||||||||||||
86Ru | 44 | 42 | 85.95731(43)# | 50# ms [> 400 ns] | 0+ | ||||||||||||||
87Ru | 44 | 43 | 86.95091(43)# | 50# ms [> 1.5 μs] | 1/2−# | ||||||||||||||
88Ru | 44 | 44 | 87.94166(32)# | 1.5(3) s | β+ (>96.4%) | 88Tc | 0+ | ||||||||||||
β+, p (<3.6%) | 87Mo | ||||||||||||||||||
89Ru | 44 | 45 | 88.937338(26) | 1.32(3) s | β+ (96.7%) | 89Tc | (9/2+) | ||||||||||||
β+, p (3.1%) | 88Mo | ||||||||||||||||||
90Ru | 44 | 46 | 89.9303444(40) | 11.7(9) s | β+ | 90Tc | 0+ | ||||||||||||
91Ru | 44 | 47 | 90.9267415(24) | 8.0(4) s | β+ | 91Tc | (9/2+) | ||||||||||||
91mRu [n 8] | −340(500) keV | 7.6(8) s | β+ (>99.9%) | 91Tc | (1/2−) | ||||||||||||||
β+, p (?%) | 90Mo | ||||||||||||||||||
92Ru | 44 | 48 | 91.9202344(29) | 3.65(5) min | β+ | 92Tc | 0+ | ||||||||||||
92mRu | 2833.9(18) keV | 100(8) ns | IT | 92Ru | (8+) | ||||||||||||||
93Ru | 44 | 49 | 92.9171044(22) | 59.7(6) s | β+ | 93Tc | (9/2)+ | ||||||||||||
93m1Ru | 734.40(10) keV | 10.8(3) s | β+ (78.0%) | 93Tc | (1/2)− | ||||||||||||||
IT (22.0%) | 93Ru | ||||||||||||||||||
β+, p (0.027%) | 92Mo | ||||||||||||||||||
93m2Ru | 2082.5(9) keV | 2.30(7) μs | IT | 93Ru | (21/2)+ | ||||||||||||||
94Ru | 44 | 50 | 93.9113429(34) | 51.8(6) min | β+ | 94Tc | 0+ | ||||||||||||
94mRu | 2644.1(4) keV | 67.5(28) μs | IT | 94Ru | 8+ | ||||||||||||||
95Ru | 44 | 51 | 94.910404(10) | 1.607(4) h | β+ | 95Tc | 5/2+ | ||||||||||||
96Ru | 44 | 52 | 95.90758891(18) | Observationally Stable [n 9] | 0+ | 0.0554(14) | |||||||||||||
97Ru | 44 | 53 | 96.9075458(30) | 2.8370(14) d | β+ | 97Tc | 5/2+ | ||||||||||||
98Ru | 44 | 54 | 97.9052867(69) | Stable | 0+ | 0.0187(3) | |||||||||||||
99Ru | 44 | 55 | 98.90593028(37) | Stable | 5/2+ | 0.1276(14) | |||||||||||||
100Ru | 44 | 56 | 99.90421046(37) | Stable | 0+ | 0.1260(7) | |||||||||||||
101Ru [n 10] | 44 | 57 | 100.90557309(44) | Stable | 5/2+ | 0.1706(2) | |||||||||||||
101mRu | 527.56(10) keV | 17.5(4) μs | IT | 101Ru | 11/2− | ||||||||||||||
102Ru [n 10] | 44 | 58 | 101.90434031(45) | Stable | 0+ | 0.3155(14) | |||||||||||||
103Ru [n 10] | 44 | 59 | 102.90631485(47) | 39.245(8) d | β− | 103Rh | 3/2+ | ||||||||||||
103mRu | 238.2(7) keV | 1.69(7) ms | IT | 103Ru | 11/2− | ||||||||||||||
104Ru [n 10] | 44 | 60 | 103.9054253(27) | Observationally Stable [n 11] | 0+ | 0.1862(27) | |||||||||||||
105Ru [n 10] | 44 | 61 | 104.9077455(27) | 4.439(11) h | β− | 105Rh | 3/2+ | ||||||||||||
105mRu | 20.606(14) keV | 340(15) ns | IT | 105Ru | 5/2+ | ||||||||||||||
106Ru [n 10] | 44 | 62 | 105.9073282(58) | 371.8(18) d | β− | 106Rh | 0+ | ||||||||||||
107Ru | 44 | 63 | 106.9099698(93) | 3.75(5) min | β− | 107Rh | (5/2)+ | ||||||||||||
108Ru | 44 | 64 | 107.9101858(93) | 4.55(5) min | β− | 108Rh | 0+ | ||||||||||||
109Ru | 44 | 65 | 108.9133237(96) | 34.4(2) s | β− | 109Rh | (5/2+) | ||||||||||||
109mRu | 96.14(15) keV | 680(30) ns | IT | 109Ru | (5/2−) | ||||||||||||||
110Ru | 44 | 66 | 109.9140385(96) | 12.04(17) s | β− | 110Rh | 0+ | ||||||||||||
111Ru | 44 | 67 | 110.917568(10) | 2.12(7) s | β− | 111Rh | 5/2+ | ||||||||||||
112Ru | 44 | 68 | 111.918807(10) | 1.75(7) s | β− | 112Rh | 0+ | ||||||||||||
113Ru | 44 | 69 | 112.922847(41) | 0.80(5) s | β− | 113Rh | (1/2+) | ||||||||||||
113mRu | 131(33) keV | 510(30) ms | β− (?%) | 113Rh | (7/2−) | ||||||||||||||
IT (?%) | 113Ru | ||||||||||||||||||
114Ru | 44 | 70 | 113.9246144(38) | 0.54(3) s | β− | 114Rh | 0+ | ||||||||||||
115Ru | 44 | 71 | 114.929033(27) | 318(19) ms | β− | 115Rh | (1/2+) | ||||||||||||
115mRu | 82(6) keV | 76(6) ms | β− (?%) | 115Rh | (7/2−) | ||||||||||||||
IT (?%) | 115Ru | ||||||||||||||||||
116Ru | 44 | 72 | 115.9312192(40) | 204(6) ms | β− | 116Rh | 0+ | ||||||||||||
117Ru | 44 | 73 | 116.93614(47) | 151(3) ms | β− | 117Rh | 3/2+# | ||||||||||||
117mRu | 185.0(4) keV | 2.49(6) μs | IT | 117Ru | 7/2−# | ||||||||||||||
118Ru | 44 | 74 | 117.93881(22)# | 99(3) ms | β− | 118Rh | 0+ | ||||||||||||
119Ru | 44 | 75 | 118.94409(32)# | 69.5(20) ms | β− | 119Rh | 3/2+# | ||||||||||||
119mRu | 227.1(7) keV | 384(22) ns | IT | 119Ru | |||||||||||||||
120Ru | 44 | 76 | 119.94662(43)# | 45(2) ms | β− | 120Rh | 0+ | ||||||||||||
121Ru | 44 | 77 | 120.95210(43)# | 29(2) ms | β− | 121Rh | 3/2+# | ||||||||||||
122Ru | 44 | 78 | 121.95515(54)# | 25(1) ms | β− | 122Rh | 0+ | ||||||||||||
123Ru | 44 | 79 | 122.96076(54)# | 19(2) ms | β− | 123Rh | 3/2+# | ||||||||||||
124Ru | 44 | 80 | 123.96394(64)# | 15(3) ms | β− | 124Rh | 0+ | ||||||||||||
125Ru | 44 | 81 | 124.96954(32)# | 12# ms [> 550 ns] | 3/2+# | ||||||||||||||
This table header & footer: |
IT: | Isomeric transition |
n: | Neutron emission |
p: | Proton emission |
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 was either in nuclear fuel cycle facilities or radioactive source production. In France levels up to 0.036mBq/m3 of air were measured. It was estimated that for distances of the order of a few tens of kilometres, contamination levels may have exceeded the limits for non-dairy foodstuffs. [8]
The ratios of the amounts of ruthenium isotopes were used to determine the age of the asteroid which exterminated the dinosaurs at the end of the Cretaceous period, and to show that it originated beyond Jupiter in the outer solar system. [9]
Daughter products other than ruthenium
ruthenium shows distinct isotopic compositions between inner and outer solar system materials