Naturally occurring

ruthenium Ruthenium is a chemical element; it has symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is unreactive to most chem ...

(₄₄Ru) is composed of seven stable

isotope Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...

s (of which two may in the future be found radioactive). Additionally, 27 radioactive isotopes have been discovered. Of these

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...

s, the most stable are ¹⁰⁶Ru, with a

half-life Half-life is a mathematical and scientific description of exponential or gradual decay. Half-life, half life or halflife may also refer to: Film * Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang * ''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 weight Relative atomic mass (symbol: ''A''; sometimes abbreviated RAM or r.a.m.), also known by the deprecated synonym atomic weight, is a dimensionless physical quantity defined as the ratio of the average mass of atoms of a chemical element in a giv ...

s 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 Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is conside ...

before the most abundant isotope, ¹⁰²Ru, is

electron capture Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Th ...

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 () 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.Ronneau, C., Cara, J., & Rimski-Korsakov, A. (1995)
Oxidation-enhanced emission of ruthenium from nuclear fuel
Journal of Environmental Radioactivity, 26(1), 63-70.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.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
Nuclear Engineering and Design, 246, 157-162. 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).

List of isotopes

, -id=Ruthenium-85 , ⁸⁵Ru , style="text-align:right" , 44 , style="text-align:right" , 41 , 84.96712(54)# , 1# ms
[>400 ns] , , , 3/2−# , , , -id=Ruthenium-86 , ⁸⁶Ru , style="text-align:right" , 44 , style="text-align:right" , 42 , 85.95731(43)# , 50# ms
[>400 ns] , , , 0+ , , , -id=Ruthenium-87 , ⁸⁷Ru , style="text-align:right" , 44 , style="text-align:right" , 43 , 86.95091(43)# , 50# ms
[>1.5 μs] , , , 1/2−# , , , -id=Ruthenium-88 , rowspan=2, ⁸⁸Ru , rowspan=2 style="text-align:right" , 44 , rowspan=2 style="text-align:right" , 44 , rowspan=2, 87.94166(32)# , rowspan=2, 1.5(3) s , beta decay, β⁺ (>96.4%) , ⁸⁸Tc , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁺, proton emission, p (<3.6%) , ⁸⁷Mo , -id=Ruthenium-89 , rowspan=2, ⁸⁹Ru , rowspan=2 style="text-align:right" , 44 , rowspan=2 style="text-align:right" , 45 , rowspan=2, 88.937338(26) , rowspan=2, 1.32(3) s , β⁺ (96.7%) , ⁸⁹Tc , rowspan=2, (9/2+) , rowspan=2, , rowspan=2, , - , β⁺, p (3.1%) , ⁸⁸Mo , -id=Ruthenium-90 , ⁹⁰Ru , style="text-align:right" , 44 , style="text-align:right" , 46 , 89.9303444(40) , 11.7(9) s , β⁺ , ⁹⁰Tc , 0+ , , , -id=Ruthenium-91 , ⁹¹Ru , style="text-align:right" , 44 , style="text-align:right" , 47 , 90.9267415(24) , 8.0(4) s , β⁺ , ⁹¹Tc , (9/2+) , , , -id=Ruthenium-91m , rowspan=2 style="text-indent:1em" , ^91mRuOrder of ground state and isomer is uncertain. , rowspan=2 colspan="3" style="text-indent:2em" , −340(500) keV , rowspan=2, 7.6(8) s , β⁺ (>99.9%) , ⁹¹Tc , rowspan=2, (1/2−) , rowspan=2, , rowspan=2, , - , β⁺, proton emission, p (?%) , ⁹⁰Mo , -id=Ruthenium-92 , ⁹²Ru , style="text-align:right" , 44 , style="text-align:right" , 48 , 91.9202344(29) , 3.65(5) min , β⁺ , ⁹²Tc , 0+ , , , -id=Ruthenium-92m , style="text-indent:1em" , ^92mRu , colspan="3" style="text-indent:2em" , 2833.9(18) keV , 100(8) ns , IT , ⁹²Ru , (8+) , , , -id=Ruthenium-93 , ⁹³Ru , style="text-align:right" , 44 , style="text-align:right" , 49 , 92.9171044(22) , 59.7(6) s , β⁺ , ⁹³Tc , (9/2)+ , , , -id=Ruthenium-93m1 , rowspan=3 style="text-indent:1em" , ^93m1Ru , rowspan=3 colspan="3" style="text-indent:2em" , 734.40(10) keV , rowspan=3, 10.8(3) s , β⁺ (78.0%) , ⁹³Tc , rowspan=3, (1/2)− , rowspan=3, , rowspan=3, , - , IT (22.0%) , ⁹³Ru , - , β⁺, p (0.027%) , ⁹²Mo , -id=Ruthenium-93m2 , style="text-indent:1em" , ^93m2Ru , colspan="3" style="text-indent:2em" , 2082.5(9) keV , 2.30(7) μs , IT , ⁹³Ru , (21/2)+ , , , -id=Ruthenium-94 , ⁹⁴Ru , style="text-align:right" , 44 , style="text-align:right" , 50 , 93.9113429(34) , 51.8(6) min , β⁺ , ⁹⁴Tc , 0+ , , , -id=Ruthenium-94m , style="text-indent:1em" , ^94mRu , colspan="3" style="text-indent:2em" , 2644.1(4) keV , 67.5(28) μs , IT , ⁹⁴Ru , 8+ , , , -id=Ruthenium-95 , ⁹⁵Ru , style="text-align:right" , 44 , style="text-align:right" , 51 , 94.910404(10) , 1.607(4) h , β⁺ , ⁹⁵Tc , 5/2+ , , , -id=Ruthenium-96 , ⁹⁶Ru , style="text-align:right" , 44 , style="text-align:right" , 52 , 95.90758891(18) , colspan=3 align=center, Observationally StableBelieved to undergo β⁺β⁺ decay to ⁹⁶Mo with a half-life over 8×10¹⁹ years , 0+ , 0.0554(14) , , -id=Ruthenium-97 , ⁹⁷Ru , style="text-align:right" , 44 , style="text-align:right" , 53 , 96.9075458(30) , 2.8370(14) d , β⁺ , ⁹⁷Tc , 5/2+ , , , -id=Ruthenium-98 , ⁹⁸Ru , style="text-align:right" , 44 , style="text-align:right" , 54 , 97.9052867(69) , colspan=3 align=center, Stable , 0+ , 0.0187(3) , , -id=Ruthenium-99 , ⁹⁹Ru , style="text-align:right" , 44 , style="text-align:right" , 55 , 98.90593028(37) , colspan=3 align=center, Stable , 5/2+ , 0.1276(14) , , -id=Ruthenium-100 , ¹⁰⁰Ru , style="text-align:right" , 44 , style="text-align:right" , 56 , 99.90421046(37) , colspan=3 align=center, Stable , 0+ , 0.1260(7) , , -id=Ruthenium-101 , ¹⁰¹RuFission product , style="text-align:right" , 44 , style="text-align:right" , 57 , 100.90557309(44) , colspan=3 align=center, Stable , 5/2+ , 0.1706(2) , , -id=Ruthenium-101m , style="text-indent:1em" , ^101mRu , colspan="3" style="text-indent:2em" , 527.56(10) keV , 17.5(4) μs , IT , ¹⁰¹Ru , 11/2− , , , -id=Ruthenium-102 , ¹⁰²Ru , style="text-align:right" , 44 , style="text-align:right" , 58 , 101.90434031(45) , colspan=3 align=center, Stable , 0+ , 0.3155(14) , , -id=Ruthenium-103 , ¹⁰³Ru , style="text-align:right" , 44 , style="text-align:right" , 59 , 102.90631485(47) , 39.245(8) d , β⁻ , ¹⁰³Rh , 3/2+ , , , -id=Ruthenium-103m , style="text-indent:1em" , ^103mRu , colspan="3" style="text-indent:2em" , 238.2(7) keV , 1.69(7) ms , IT , ¹⁰³Ru , 11/2− , , , -id=Ruthenium-104 , ¹⁰⁴Ru , style="text-align:right" , 44 , style="text-align:right" , 60 , 103.9054253(27) , colspan=3 align=center, Observationally StableBelieved to undergo β⁻β⁻ decay to ¹⁰⁴Pd , 0+ , 0.1862(27) , , -id=Ruthenium-105 , ¹⁰⁵Ru , style="text-align:right" , 44 , style="text-align:right" , 61 , 104.9077455(27) , 4.439(11) h , β⁻ , ¹⁰⁵Rh , 3/2+ , , , -id=Ruthenium-105m , style="text-indent:1em" , ^105mRu , colspan="3" style="text-indent:2em" , 20.606(14) keV , 340(15) ns , IT , ¹⁰⁵Ru , 5/2+ , , , -id=Ruthenium-106 , ¹⁰⁶Ru , style="text-align:right" , 44 , style="text-align:right" , 62 , 105.9073282(58) , 371.8(18) d , β⁻ , ¹⁰⁶Rh , 0+ , , , -id=Ruthenium-107 , ¹⁰⁷Ru , style="text-align:right" , 44 , style="text-align:right" , 63 , 106.9099698(93) , 3.75(5) min , β⁻ , ¹⁰⁷Rh , (5/2)+ , , , -id=Ruthenium-108 , ¹⁰⁸Ru , style="text-align:right" , 44 , style="text-align:right" , 64 , 107.9101858(93) , 4.55(5) min , β⁻ , ¹⁰⁸Rh , 0+ , , , -id=Ruthenium-109 , ¹⁰⁹Ru , style="text-align:right" , 44 , style="text-align:right" , 65 , 108.9133237(96) , 34.4(2) s , β⁻ , ¹⁰⁹Rh , (5/2+) , , , -id=Ruthenium-109m , style="text-indent:1em" , ^109mRu , colspan="3" style="text-indent:2em" , 96.14(15) keV , 680(30) ns , IT , ¹⁰⁹Ru , (5/2−) , , , -id=Ruthenium-110 , ¹¹⁰Ru , style="text-align:right" , 44 , style="text-align:right" , 66 , 109.9140385(96) , 12.04(17) s , β⁻ , ¹¹⁰Rh , 0+ , , , -id=Ruthenium-111 , ¹¹¹Ru , style="text-align:right" , 44 , style="text-align:right" , 67 , 110.917568(10) , 2.12(7) s , β⁻ , ¹¹¹Rh , 5/2+ , , , -id=Ruthenium-112 , ¹¹²Ru , style="text-align:right" , 44 , style="text-align:right" , 68 , 111.918807(10) , 1.75(7) s , β⁻ , ¹¹²Rh , 0+ , , , -id=Ruthenium-113 , ¹¹³Ru , style="text-align:right" , 44 , style="text-align:right" , 69 , 112.922847(41) , 0.80(5) s , β⁻ , ¹¹³Rh , (1/2+) , , , -id=Ruthenium-113m , rowspan=2 style="text-indent:1em" , ^113mRu , rowspan=2 colspan="3" style="text-indent:2em" , 131(33) keV , rowspan=2, 510(30) ms , β⁻ (?%) , ¹¹³Rh , rowspan=2, (7/2−) , rowspan=2, , rowspan=2, , - , IT (?%) , ¹¹³Ru , -id=Ruthenium-114 , ¹¹⁴Ru , style="text-align:right" , 44 , style="text-align:right" , 70 , 113.9246144(38) , 0.54(3) s , β⁻ , ¹¹⁴Rh , 0+ , , , -id=Ruthenium-115 , ¹¹⁵Ru , style="text-align:right" , 44 , style="text-align:right" , 71 , 114.929033(27) , 318(19) ms , β⁻ , ¹¹⁵Rh , (1/2+) , , , -id=Ruthenium-115m , rowspan=2 style="text-indent:1em" , ^115mRu , rowspan=2 colspan="3" style="text-indent:2em" , 82(6) keV , rowspan=2, 76(6) ms , β⁻ (?%) , ¹¹⁵Rh , rowspan=2, (7/2−) , rowspan=2, , rowspan=2, , - , IT (?%) , ¹¹⁵Ru , -id=Ruthenium-116 , ¹¹⁶Ru , style="text-align:right" , 44 , style="text-align:right" , 72 , 115.9312192(40) , 204(6) ms , β⁻ , ¹¹⁶Rh , 0+ , , , -id=Ruthenium-117 , ¹¹⁷Ru , style="text-align:right" , 44 , style="text-align:right" , 73 , 116.93614(47) , 151(3) ms , β⁻ , ¹¹⁷Rh , 3/2+# , , , -id=Ruthenium-117m , style="text-indent:1em" , ^117mRu , colspan="3" style="text-indent:2em" , 185.0(4) keV , 2.49(6) μs , IT , ¹¹⁷Ru , 7/2−# , , , -id=Ruthenium-118 , ¹¹⁸Ru , style="text-align:right" , 44 , style="text-align:right" , 74 , 117.93881(22)# , 99(3) ms , β⁻ , ¹¹⁸Rh , 0+ , , , -id=Ruthenium-119 , ¹¹⁹Ru , style="text-align:right" , 44 , style="text-align:right" , 75 , 118.94409(32)# , 69.5(20) ms , β⁻ , ¹¹⁹Rh , 3/2+# , , , -id=Ruthenium-119m , style="text-indent:1em" , ^119mRu , colspan="3" style="text-indent:2em" , 227.1(7) keV , 384(22) ns , IT , ¹¹⁹Ru , , , , -id=Ruthenium-120 , ¹²⁰Ru , style="text-align:right" , 44 , style="text-align:right" , 76 , 119.94662(43)# , 45(2) ms , β⁻ , ¹²⁰Rh , 0+ , , , -id=Ruthenium-121 , ¹²¹Ru , style="text-align:right" , 44 , style="text-align:right" , 77 , 120.95210(43)# , 29(2) ms , β⁻ , ¹²¹Rh , 3/2+# , , , -id=Ruthenium-122 , ¹²²Ru , style="text-align:right" , 44 , style="text-align:right" , 78 , 121.95515(54)# , 25(1) ms , β⁻ , ¹²²Rh , 0+ , , , -id=Ruthenium-123 , ¹²³Ru , style="text-align:right" , 44 , style="text-align:right" , 79 , 122.96076(54)# , 19(2) ms , β⁻ , ¹²³Rh , 3/2+# , , , -id=Ruthenium-124 , ¹²⁴Ru , style="text-align:right" , 44 , style="text-align:right" , 80 , 123.96394(64)# , 15(3) ms , β⁻ , ¹²⁴Rh , 0+ , , , -id=Ruthenium-125 , ¹²⁵Ru , style="text-align:right" , 44 , style="text-align:right" , 81 , 124.96954(32)# , 12# ms
[>550 ns] , , , 3/2+# , , * 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.
Detection of ruthenium 106 in France and in Europe, IRSN France (9 Nov 2017) Ruthenium-96

References

* Isotope masses from: ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Navbox element isotopes Isotopes of ruthenium, Ruthenium Lists of isotopes by element, Ruthenium

List of isotopes

See also

References