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Standard atomic weight Ar°(W) | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Naturally occurring tungsten (74W) consists of five isotopes. Four are considered stable (W, W, W, and W) and one is slightly radioactive, W, with an extremely long half-life of 1.8 ± 0.2 exayears (10 years). On average, two alpha decays of W occur per gram of natural tungsten per year, so for most practical purposes, W can be considered stable. Theoretically, all five can decay into isotopes of element 72 (hafnium) by alpha emission, but only W has been observed to do so. The other naturally occurring isotopes have not been observed to decay (they are observationally stable), and lower bounds for their half-lives have been established:
- W, t1/2 > 7.7×10 years
- W, t1/2 > 4.1×10 years
- W, t1/2 > 8.9×10 years
- W, t1/2 > 8.2×10 years
Thirty-four artificial radioisotopes of tungsten have been characterized with mass numbers ranging from 156 to 194, the most stable of which are W with a half-life of 121.2 days, W with a half-life of 75.1 days, W with a half-life of 69.4 days and W with a half-life of 21.6 days. All of the remaining radioactive isotopes have half-lives of less than 24 hours, and most of these have half-lives that are less than 8 minutes. Tungsten also has 11 meta states with mass numbers of 158, 179, with 3, 180, with 2, 183, 185, 186, with 2, and 190, the most stable being W (t1/2 6.4 minutes).
List of isotopes
Nuclide |
Z | N | Isotopic mass (Da) |
Half-life |
Decay mode |
Daughter isotope |
Spin and parity |
Natural abundance (mole fraction) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy | Normal proportion | Range of variation | |||||||||||||||||
W | 74 | 82 | 157+57 −34 ms |
β | Ta | 0+ | |||||||||||||
W | 74 | 83 | 275(40) ms | β | Ta | (7/2−) | |||||||||||||
W | 74 | 84 | 157.97456(54)# | 1.37(17) ms | α | Hf | 0+ | ||||||||||||
W | 1889(8) keV | 143(19) μs | α | Hf | 8+ | ||||||||||||||
W | 74 | 85 | 158.97292(43)# | 8.2(7) ms | α (82%) | Hf | 7/2−# | ||||||||||||
β (18%) | Ta | ||||||||||||||||||
W | 74 | 86 | 159.96848(22) | 90(5) ms | α (87%) | Hf | 0+ | ||||||||||||
β (14%) | Ta | ||||||||||||||||||
W | 74 | 87 | 160.96736(21)# | 409(16) ms | α (73%) | Hf | 7/2−# | ||||||||||||
β (23%) | Ta | ||||||||||||||||||
W | 74 | 88 | 161.963497(19) | 1.36(7) s | β (53%) | Ta | 0+ | ||||||||||||
α (47%) | Hf | ||||||||||||||||||
W | 74 | 89 | 162.96252(6) | 2.8(2) s | β (59%) | Ta | 3/2−# | ||||||||||||
α (41%) | Hf | ||||||||||||||||||
W | 74 | 90 | 163.958954(13) | 6.3(2) s | β (97.4%) | Ta | 0+ | ||||||||||||
α (2.6%) | Hf | ||||||||||||||||||
W | 74 | 91 | 164.958280(27) | 5.1(5) s | β (99.8%) | Ta | 3/2−# | ||||||||||||
α (.2%) | Hf | ||||||||||||||||||
W | 74 | 92 | 165.955027(11) | 19.2(6) s | β (99.96%) | Ta | 0+ | ||||||||||||
α (.035%) | Hf | ||||||||||||||||||
W | 74 | 93 | 166.954816(21) | 19.9(5) s | β (>99.9%) | Ta | 3/2−# | ||||||||||||
α (<.1%) | Hf | ||||||||||||||||||
W | 74 | 94 | 167.951808(17) | 51(2) s | β (99.99%) | Ta | 0+ | ||||||||||||
α (.0319%) | Hf | ||||||||||||||||||
W | 74 | 95 | 168.951779(17) | 76(6) s | β | Ta | (5/2−) | ||||||||||||
W | 74 | 96 | 169.949228(16) | 2.42(4) min | β(99%) | Ta | 0+ | ||||||||||||
α (1%) | Hf | ||||||||||||||||||
W | 74 | 97 | 170.94945(3) | 2.38(4) min | β | Ta | (5/2−) | ||||||||||||
W | 74 | 98 | 171.94729(3) | 6.6(9) min | β | Ta | 0+ | ||||||||||||
W | 74 | 99 | 172.94769(3) | 7.6(2) min | β | Ta | 5/2− | ||||||||||||
W | 74 | 100 | 173.94608(3) | 33.2(21) min | β | Ta | 0+ | ||||||||||||
W | 74 | 101 | 174.94672(3) | 35.2(6) min | β | Ta | (1/2−) | ||||||||||||
W | 74 | 102 | 175.94563(3) | 2.5(1) h | EC | Ta | 0+ | ||||||||||||
W | 74 | 103 | 176.94664(3) | 132(2) min | β | Ta | 1/2− | ||||||||||||
W | 74 | 104 | 177.945876(16) | 21.6(3) d | EC | Ta | 0+ | ||||||||||||
W | 74 | 105 | 178.947070(17) | 37.05(16) min | β | Ta | (7/2)− | ||||||||||||
W | 221.926(8) keV | 6.40(7) min | IT (99.72%) | W | (1/2)− | ||||||||||||||
β (.28%) | Ta | ||||||||||||||||||
W | 1631.90(8) keV | 390(30) ns | (21/2+) | ||||||||||||||||
W | 3348.45(16) keV | 750(80) ns | (35/2−) | ||||||||||||||||
W | 74 | 106 | 179.946704(4) | 1.8(0.2)×10 y | α | Hf | 0+ | 0.0012(1) | |||||||||||
W | 1529.04(3) keV | 5.47(9) ms | IT | W | 8− | ||||||||||||||
W | 3264.56(21) keV | 2.33(19) μs | 14− | ||||||||||||||||
W | 74 | 107 | 180.948197(5) | 121.2(2) d | EC | Ta | 9/2+ | ||||||||||||
W | 74 | 108 | 181.9482042(9) | Observationally Stable | 0+ | 0.2650(16) | |||||||||||||
W | 74 | 109 | 182.9502230(9) | Observationally Stable | 1/2− | 0.1431(4) | |||||||||||||
W | 309.493(3) keV | 5.2(3) s | IT | W | 11/2+ | ||||||||||||||
W | 74 | 110 | 183.9509312(9) | Observationally Stable | 0+ | 0.3064(2) | |||||||||||||
W | 74 | 111 | 184.9534193(10) | 75.1(3) d | β | Re | 3/2− | ||||||||||||
W | 197.43(5) keV | 1.597(4) min | IT | W | 11/2+ | ||||||||||||||
W | 74 | 112 | 185.9543641(19) | Observationally Stable | 0+ | 0.2843(19) | |||||||||||||
W | 1517.2(6) keV | 18(1) μs | (7−) | ||||||||||||||||
W | 3542.8(21) keV | >3 ms | (16+) | ||||||||||||||||
W | 74 | 113 | 186.9571605(19) | 23.72(6) h | β | Re | 3/2− | ||||||||||||
W | 74 | 114 | 187.958489(4) | 69.78(5) d | β | Re | 0+ | ||||||||||||
W | 74 | 115 | 188.96191(21) | 11.6(3) min | β | Re | (3/2−) | ||||||||||||
W | 74 | 116 | 189.96318(18) | 30.0(15) min | β | Re | 0+ | ||||||||||||
W | 2381(5) keV | <3.1 ms | (10−) | ||||||||||||||||
W | 74 | 117 | 190.96660(21)# | 20# s |
3/2−# | ||||||||||||||
W | 74 | 118 | 191.96817(64)# | 10# s |
0+ | ||||||||||||||
This table header & footer: |
- W – 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).
- Bold half-life – nearly stable, half-life longer than age of universe.
- ^ # – 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 - 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.
- Primordial radionuclide
- Believed to undergo α decay to Hf with a half-life over 7.7×10 y
- Believed to undergo α decay to Hf with a half-life over 4.1×10 y
- Believed to undergo α decay to Hf with a half-life over 8.9×10 y
- Believed to undergo α decay to Hf or ββ decay to Os with a half-life over 8.2×10 y
References
- "Standard Atomic Weights: Tungsten". CIAAW. 1991.
- Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (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.
- Briscoe, A. D.; Page, R. D.; Uusitalo, J.; et al. (2023). "Decay spectroscopy at the two-proton drip line: Radioactivity of the new nuclides Os and W". Physics Letters B. 47 (138310). doi:10.1016/j.physletb.2023.138310. hdl:10272/23933.
- Bianco, L.; Page, R. D.; Darby, I. G.; et al. (7 June 2010). "Discovery of W and Os" (PDF). Physics Letters B. 690 (1): 15–18. Bibcode:2010PhLB..690...15B. doi:10.1016/j.physletb.2010.04.056. ISSN 0370-2693. S2CID 117121162. Retrieved 11 June 2023.
- 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, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- Isotopic compositions and standard atomic masses from:
- de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
- 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.
- "News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
- 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, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.