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Isotopes of iridium
Topic: Physics
From HandWiki - Reading time: 6 min
Short description: Nuclides with atomic number of 77 but with different mass numbers
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| Standard atomic weight Ar, standard(Ir) |
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There are two natural isotopes of iridium (77Ir), and 37 radioisotopes, the most stable radioisotope being 192Ir with a half-life of 73.83 days, and many nuclear isomers, the most stable of which is 192m2Ir with a half-life of 241 years. All other isomers have half-lives under a year, most under a day. All isotopes of iridium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.[2]
List of isotopes
| Nuclide[3] [n 1] |
Z | N | Isotopic mass (u)[4] [n 2][n 3] |
Half-life [n 4] |
Decay mode [n 5] |
Daughter isotope [n 6][n 7] |
Spin and parity [n 8][n 4] |
Physics:Natural abundance (mole fraction) | |
|---|---|---|---|---|---|---|---|---|---|
| Excitation energy[n 4] | Normal proportion | Range of variation | |||||||
| 164Ir[5] | 77 | 87 | 163.99220(44)# | <0.5 µs | p? | 163Os | 2−# | ||
| 164mIr | 270(110)# keV | 70(10) µs | p (96%) | 163Os | 9+# | ||||
| α (4%) | 160mRe | ||||||||
| 165Ir | 77 | 88 | 164.98752(23)# | 1.20+0.82 −0.74 μs[6] |
p | 164Os | (1/2+) | ||
| 165mIr[7] | ~255 keV | 340(40) µs | p (88%) | 164Os | (11/2−) | ||||
| α (12%) | 161mRe | ||||||||
| 166Ir | 77 | 89 | 165.98582(22)# | 10.5(22) ms | α (93%) | 162Re | (2−) | ||
| p (7%) | 165Os | ||||||||
| 166mIr | 172(6) keV | 15.1(9) ms | α (98.2%) | 162Re | (9+) | ||||
| p (1.8%) | 165Os | ||||||||
| 167Ir | 77 | 90 | 166.981665(20) | 35.2(20) ms | α (48%) | 163Re | 1/2+ | ||
| p (32%) | 166Os | ||||||||
| β+ (20%) | 167Os | ||||||||
| 167mIr | 175.3(22) keV | 30.0(6) ms | α (80%) | 163Re | 11/2− | ||||
| β+ (20%) | 167Os | ||||||||
| p (.4%) | 166Os | ||||||||
| 168Ir | 77 | 91 | 167.97988(16)# | 161(21) ms | α | 164Re | (2-) | ||
| β+ (rare) | 168Os | ||||||||
| 168mIr | 50(100)# keV | 125(40) ms | α | 164Re | (9+) | ||||
| 169Ir | 77 | 92 | 168.976295(28) | 780(360) ms [0.64(+46−24) s] |
α | 165Re | (1/2+) | ||
| β+ (rare) | 169Os | ||||||||
| 169mIr | 154(24) keV | 308(22) ms | α (72%) | 165Re | (11/2−) | ||||
| β+ (28%) | 169Os | ||||||||
| 170Ir | 77 | 93 | 169.97497(11)# | 910(150) ms [0.87(+18−12) s] |
β+ (64%) | 170Os | low# | ||
| α (36%) | 166Re | ||||||||
| 170mIr | 160(50)# keV | 440(60) ms | α (36%) | 166Re | (8+) | ||||
| β+ | 170Os | ||||||||
| IT | 170Ir | ||||||||
| 171Ir | 77 | 94 | 170.97163(4) | 3.6(10) s [3.2(+13−7) s] |
α (58%) | 167Re | 1/2+ | ||
| β+ (42%) | 171Os | ||||||||
| 171mIr | 180(30)# keV | 1.40(10) s | (11/2−) | ||||||
| 172Ir | 77 | 95 | 171.970610(30) | 4.4(3) s | β+ (98%) | 172Os | (3+) | ||
| α (2%) | 168Re | ||||||||
| 172mIr | 280(100)# keV | 2.0(1) s | β+ (77%) | 172Os | (7+) | ||||
| α (23%) | 168Re | ||||||||
| 173Ir | 77 | 96 | 172.967502(15) | 9.0(8) s | β+ (93%) | 173Os | (3/2+,5/2+) | ||
| α (7%) | 169Re | ||||||||
| 173mIr | 253(27) keV | 2.20(5) s | β+ (88%) | 173Os | (11/2−) | ||||
| α (12%) | 169Re | ||||||||
| 174Ir | 77 | 97 | 173.966861(30) | 7.9(6) s | β+ (99.5%) | 174Os | (3+) | ||
| α (.5%) | 170Re | ||||||||
| 174mIr | 193(11) keV | 4.9(3) s | β+ (99.53%) | 174Os | (7+) | ||||
| α (.47%) | 170Re | ||||||||
| 175Ir | 77 | 98 | 174.964113(21) | 9(2) s | β+ (99.15%) | 175Os | (5/2−) | ||
| α (.85%) | 171Re | ||||||||
| 176Ir | 77 | 99 | 175.963649(22) | 8.3(6) s | β+ (97.9%) | 176Os | |||
| α (2.1%) | 172Re | ||||||||
| 177Ir | 77 | 100 | 176.961302(21) | 30(2) s | β+ (99.94%) | 177Os | 5/2− | ||
| α (.06%) | 173Re | ||||||||
| 178Ir | 77 | 101 | 177.961082(21) | 12(2) s | β+ | 178Os | |||
| 179Ir | 77 | 102 | 178.959122(12) | 79(1) s | β+ | 179Os | (5/2)− | ||
| 180Ir | 77 | 103 | 179.959229(23) | 1.5(1) min | β+ | 180Os | (4,5)(+#) | ||
| 181Ir | 77 | 104 | 180.957625(28) | 4.90(15) min | β+ | 181Os | (5/2)− | ||
| 182Ir | 77 | 105 | 181.958076(23) | 15(1) min | β+ | 182Os | (3+) | ||
| 183Ir | 77 | 106 | 182.956846(27) | 57(4) min | β+ ( 99.95%) | 183Os | 5/2− | ||
| α (.05%) | 179Re | ||||||||
| 184Ir | 77 | 107 | 183.95748(3) | 3.09(3) h | β+ | 184Os | 5− | ||
| 184m1Ir | 225.65(11) keV | 470(30) µs | 3+ | ||||||
| 184m2Ir | 328.40(24) keV | 350(90) ns | (7)+ | ||||||
| 185Ir | 77 | 108 | 184.95670(3) | 14.4(1) h | β+ | 185Os | 5/2− | ||
| 186Ir | 77 | 109 | 185.957946(18) | 16.64(3) h | β+ | 186Os | 5+ | ||
| 186mIr | 0.8(4) keV | 1.92(5) h | β+ | 186Os | 2− | ||||
| IT (rare) | 186Ir | ||||||||
| 187Ir | 77 | 110 | 186.957363(7) | 10.5(3) h | β+ | 187Os | 3/2+ | ||
| 187m1Ir | 186.15(4) keV | 30.3(6) ms | IT | 187Ir | 9/2− | ||||
| 187m2Ir | 433.81(9) keV | 152(12) ns | 11/2− | ||||||
| 188Ir | 77 | 111 | 187.958853(8) | 41.5(5) h | β+ | 188Os | 1− | ||
| 188mIr | 970(30) keV | 4.2(2) ms | IT | 188Ir | 7+# | ||||
| β+ (rare) | 188Os | ||||||||
| 189Ir | 77 | 112 | 188.958719(14) | 13.2(1) d | EC | 189Os | 3/2+ | ||
| 189m1Ir | 372.18(4) keV | 13.3(3) ms | IT | 189Ir | 11/2− | ||||
| 189m2Ir | 2333.3(4) keV | 3.7(2) ms | (25/2)+ | ||||||
| 190Ir | 77 | 113 | 189.9605460(18) | 11.78(10) d | β+ | 190Os | 4− | ||
| 190m1Ir | 26.1(1) keV | 1.120(3) h | IT | 190Ir | (1−) | ||||
| 190m2Ir | 36.154(25) keV | >2 µs | (4)+ | ||||||
| 190m3Ir | 376.4(1) keV | 3.087(12) h | (11)− | ||||||
| 191Ir | 77 | 114 | 190.9605940(18) | Observationally Stable[n 9] | 3/2+ | 0.373(2) | |||
| 191m1Ir | 171.24(5) keV | 4.94(3) s | IT | 191Ir | 11/2− | ||||
| 191m2Ir | 2120(40) keV | 5.5(7) s | |||||||
| 192Ir | 77 | 115 | 191.9626050(18) | 73.827(13) d | β− (95.24%) | 192Pt | 4+ | ||
| EC (4.76%) | 192Os | ||||||||
| 192m1Ir | 56.720(5) keV | 1.45(5) min | 1− | ||||||
| 192m2Ir | 168.14(12) keV | 241(9) y | (11−) | ||||||
| 193Ir | 77 | 116 | 192.9629264(18) | Observationally Stable[n 10] | 3/2+ | 0.627(2) | |||
| 193mIr | 80.240(6) keV | 10.53(4) d | IT | 193Ir | 11/2− | ||||
| 194Ir | 77 | 117 | 193.9650784(18) | 19.28(13) h | β− | 194Pt | 1− | ||
| 194m1Ir | 147.078(5) keV | 31.85(24) ms | IT | 194Ir | (4+) | ||||
| 194m2Ir | 370(70) keV | 171(11) d | (10,11)(−#) | ||||||
| 195Ir | 77 | 118 | 194.9659796(18) | 2.5(2) h | β− | 195Pt | 3/2+ | ||
| 195mIr | 100(5) keV | 3.8(2) h | β− (95%) | 195Pt | 11/2− | ||||
| IT (5%) | 195Ir | ||||||||
| 196Ir | 77 | 119 | 195.96840(4) | 52(1) s | β− | 196Pt | (0−) | ||
| 196mIr | 210(40) keV | 1.40(2) h | β− (99.7%) | 196Pt | (10,11−) | ||||
| IT | 196Ir | ||||||||
| 197Ir | 77 | 120 | 196.969653(22) | 5.8(5) min | β− | 197Pt | 3/2+ | ||
| 197mIr | 115(5) keV | 8.9(3) min | β− (99.75%) | 197Pt | 11/2− | ||||
| IT (.25%) | 197Ir | ||||||||
| 198Ir | 77 | 121 | 197.97228(21)# | 8(1) s | β− | 198Pt | |||
| 199Ir | 77 | 122 | 198.97380(4) | 7(5) s | β− | 199Pt | 3/2+# | ||
| 199mIr | 130(40)# keV | 235(90) ns | IT | 199Ir | 11/2−# | ||||
| 200Ir | 77 | 123 | 199.976800(210)# | 43(6) s | β− | 200Pt | (2-, 3-) | ||
| 201Ir | 77 | 124 | 200.978640(210)# | 21(5) s | β− | 201Pt | (3/2+) | ||
| 202Ir | 77 | 125 | 201.981990(320)# | 11(3) s | β− | 202Pt | (2-) | ||
| 202mIr | 2000(1000)# keV | 3.4(0.6) µs | IT | 202Ir | |||||
- ↑ mIr – Excited nuclear isomer.
- ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
- ↑ 4.0 4.1 4.2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- ↑
Modes of decay:
EC: Electron capture IT: Isomeric transition
p: Proton emission - ↑ Bold italics symbol as daughter – Daughter product is nearly stable.
- ↑ Bold symbol as daughter – Daughter product is stable.
- ↑ ( ) spin value – Indicates spin with weak assignment arguments.
- ↑ Believed to undergo α decay to 187Re
- ↑ Believed to undergo α decay to 189Re
Iridium-192
Iridium-192 (symbol 192Ir) is a radioactive isotope of iridium, with a half-life of 73.83 days.[8] It decays by emitting beta (β) particles and gamma (γ) radiation. About 96% of 192Ir decays occur via emission of β and γ radiation, leading to 192Pt. Some of the β particles are captured by other 192Ir nuclei, which are then converted to 192Os. Electron capture is responsible for the remaining 4% of 192Ir decays.[9] Iridium-192 is normally produced by neutron activation of natural-abundance iridium metal.[10]
Iridium-192 is a very strong gamma ray emitter, with a gamma dose-constant of approximately 1.54 μSv·h−1·MBq−1 at 30 cm, and a specific activity of 341 TBq·g−1 (9.22 kCi·g−1).[11][12] There are seven principal energy packets produced during its disintegration process ranging from just over 0.2 to about 0.6 MeV.
The 192m2Ir isomer is unusual, both for its long half-life for an isomer, and that said half-life greatly exceeds that of the ground state of the same isotope.
References
- ↑ Meija, Juris; Coplen, Tyler B.; Berglund, Michael; Brand, Willi A.; De Bièvre, Paul; Gröning, Manfred; Holden, Norman E.; Irrgeher, Johanna et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry 88 (3): 265–91. doi:10.1515/pac-2015-0305.
- ↑ Belli, P.; Bernabei, R.; Danevich, F. A. et al. (2019). "Experimental searches for rare alpha and beta decays". European Physical Journal A 55 (8): 140–1–140–7. doi:10.1140/epja/i2019-12823-2. ISSN 1434-601X. Bibcode: 2019EPJA...55..140B.
- ↑ Half-life, decay mode, nuclear spin, and isotopic composition is sourced in:
Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties". Chinese Physics C 41 (3): 030001. doi:10.1088/1674-1137/41/3/030001. Bibcode: 2017ChPhC..41c0001A. https://www-nds.iaea.org/amdc/ame2016/NUBASE2016.pdf. - ↑ Wang, M.; Audi, G.; Kondev, F. G.; Huang, W. J.; Naimi, S.; Xu, X. (2017). "The AME2016 atomic mass evaluation (II). Tables, graphs, and references". Chinese Physics C 41 (3): 030003-1—030003-442. doi:10.1088/1674-1137/41/3/030003. http://nuclearmasses.org/resources_folder/Wang_2017_Chinese_Phys_C_41_030003.pdf.
- ↑ Drummond, M. C.; O'Donnell, D.; Page, R. D.; Joss, D. T.; Capponi, L.; Cox, D. M.; Darby, I. G.; Donosa, L. et al. (16 June 2014). "α decay of the π h 11 / 2 isomer in Ir 164" (in en). Physical Review C 89 (6): 064309. doi:10.1103/PhysRevC.89.064309. ISSN 0556-2813. Bibcode: 2014PhRvC..89f4309D. https://journals.aps.org/prc/pdf/10.1103/PhysRevC.89.064309. Retrieved 21 June 2023.
- ↑ Hilton, Joshua Ben. "Decays of new nuclides 169Au, 170Hg, 165Pt and the ground state of 165Ir discovered using MARA". University of Liverpool. https://www.proquest.com/docview/2448649087.
- ↑ Drummond, M. C.; O'Donnell, D.; Page, R. D.; Joss, D. T.; Capponi, L.; Cox, D. M.; Darby, I. G.; Donosa, L. et al. (16 June 2014). "α decay of the π h 11 / 2 isomer in Ir 164" (in en). Physical Review C 89 (6): 064309. doi:10.1103/PhysRevC.89.064309. ISSN 0556-2813. Bibcode: 2014PhRvC..89f4309D. https://journals.aps.org/prc/pdf/10.1103/PhysRevC.89.064309. Retrieved 21 June 2023.
- ↑ "Radioisotope Brief: Iridium-192 (Ir-192)". http://emergency.cdc.gov/radiation/isotopes/iridium.asp.
- ↑ Baggerly, Leo L. (1956). The radioactive decay of Iridium-192 (PDF) (Ph.D. thesis). Pasadena, Calif.: California Institute of Technology. pp. 1, 2, 7. doi:10.7907/26VA-RB25.
- ↑ "Isotope Supplier: Stable Isotopes and Radioisotopes from ISOFLEX - Iridium-192" (in en). https://www.isoflex.com/products/radioisotopes/iridium-isotopes.
- ↑ Delacroix, D; Guerre, J P; Leblanc, P; Hickman, C (2002). "Radionuclide and Radiation Protection Data Handbook". 98 (2nd ed.). Ashford, Kent: Nuclear Technology Publishing. 9–168. doi:10.1093/OXFORDJOURNALS.RPD.A006705. ISBN 1870965876. https://pdfs.semanticscholar.org/fbb1/7281dae98db83fe20df96b9d879c0c73b199.pdf.
- ↑ Unger, L M; Trubey, D K (May 1982). Specific Gamma-Ray Dose Constants for Nuclides Important to Dosimetry and Radiological Assessment (Report). Oak Ridge National Laboratory. https://www.orau.org/documents/ivhp/health-physics/ornl-rsic-45.pdf.
- 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, doi:10.1016/j.nuclphysa.2003.11.001, Bibcode: 2003NuPhA.729....3A, https://hal.archives-ouvertes.fr/in2p3-00020241/document
- Isotopic compositions and standard atomic masses from:
- 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.
- 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, doi:10.1016/j.nuclphysa.2003.11.001, Bibcode: 2003NuPhA.729....3A, https://hal.archives-ouvertes.fr/in2p3-00020241/document
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory. http://www.nndc.bnl.gov/nudat2/.
- Lide, David R., ed (2004). "11. Table of the Isotopes". CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
External links
- NLM Hazardous Substances Databank – Iridium, Radioactive (referring to iridium-192)
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