Isotopes of hafnium
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Standard atomic weight Ar, standard(Hf) | 178.486(6)[1][2] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Natural hafnium (72Hf) consists of five stable isotopes (176Hf, 177Hf, 178Hf, 179Hf, and 180Hf) and one very long-lived radioisotope, 174Hf, with a half-life of 2×1015 years. In addition, there are 30 other known radionuclides, the most stable of which is 182Hf with a half-life of 8.9×106 years. No other radioisotope has a half-life over 1.87 years. Most isotopes have half-lives under 1 minute. There are also 26 known nuclear isomers, the most stable of which is 178m2Hf with a half-life of 31 years. All isotopes of hafnium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.
List of isotopes[]
Nuclide [n 1] |
Z | N | Isotopic mass (Da) [n 2][n 3] |
Half-life [n 4][n 5] |
Decay mode [n 6] |
Daughter isotope [n 7] |
Spin and parity [n 8][n 5] |
Natural abundance (mole fraction) | |||||||||||
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Excitation energy[n 5] | Normal proportion | Range of variation | |||||||||||||||||
153Hf | 72 | 81 | 152.97069(54)# | 400# ms [>200 ns] | 1/2+# | ||||||||||||||
153mHf | 750(100)# keV | 500# ms | 11/2−# | ||||||||||||||||
154Hf | 72 | 82 | 153.96486(54)# | 2(1) s | β+ | 154Lu | 0+ | ||||||||||||
α (rare) | 150Yb | ||||||||||||||||||
155Hf | 72 | 83 | 154.96339(43)# | 890(120) ms | β+ | 155Lu | 7/2−# | ||||||||||||
α (rare) | 151Yb | ||||||||||||||||||
156Hf | 72 | 84 | 155.95936(22) | 23(1) ms | α (97%) | 152Yb | 0+ | ||||||||||||
β+ (3%) | 156Lu | ||||||||||||||||||
156mHf | 1959.0(10) keV | 480(40) μs | 8+ | ||||||||||||||||
157Hf | 72 | 85 | 156.95840(21)# | 115(1) ms | α (86%) | 153Yb | 7/2− | ||||||||||||
β+ (14%) | 157Lu | ||||||||||||||||||
158Hf | 72 | 86 | 157.954799(19) | 2.84(7) s | β+ (55%) | 158Lu | 0+ | ||||||||||||
α (45%) | 154Yb | ||||||||||||||||||
159Hf | 72 | 87 | 158.953995(18) | 5.20(10) s | β+ (59%) | 159Lu | 7/2−# | ||||||||||||
α (41%) | 155Yb | ||||||||||||||||||
160Hf | 72 | 88 | 159.950684(12) | 13.6(2) s | β+ (99.3%) | 160Lu | 0+ | ||||||||||||
α (.7%) | 156Yb | ||||||||||||||||||
161Hf | 72 | 89 | 160.950275(24) | 18.2(5) s | β+ (99.7%) | 161Lu | 3/2−# | ||||||||||||
α (.3%) | 157Yb | ||||||||||||||||||
162Hf | 72 | 90 | 161.94721(1) | 39.4(9) s | β+ (99.99%) | 162Lu | 0+ | ||||||||||||
α (.008%) | 158Yb | ||||||||||||||||||
163Hf | 72 | 91 | 162.94709(3) | 40.0(6) s | β+ | 163Lu | 3/2−# | ||||||||||||
α (10−4%) | 159Yb | ||||||||||||||||||
164Hf | 72 | 92 | 163.944367(22) | 111(8) s | β+ | 164Lu | 0+ | ||||||||||||
165Hf | 72 | 93 | 164.94457(3) | 76(4) s | β+ | 165Lu | (5/2−) | ||||||||||||
166Hf | 72 | 94 | 165.94218(3) | 6.77(30) min | β+ | 166Lu | 0+ | ||||||||||||
167Hf | 72 | 95 | 166.94260(3) | 2.05(5) min | β+ | 167Lu | (5/2)− | ||||||||||||
168Hf | 72 | 96 | 167.94057(3) | 25.95(20) min | β+ | 168Lu | 0+ | ||||||||||||
169Hf | 72 | 97 | 168.94126(3) | 3.24(4) min | β+ | 169Lu | (5/2)− | ||||||||||||
170Hf | 72 | 98 | 169.93961(3) | 16.01(13) h | EC | 170Lu | 0+ | ||||||||||||
171Hf | 72 | 99 | 170.94049(3) | 12.1(4) h | β+ | 171Lu | 7/2(+) | ||||||||||||
171mHf | 21.93(9) keV | 29.5(9) s | IT | 171Hf | 1/2(−) | ||||||||||||||
172Hf | 72 | 100 | 171.939448(26) | 1.87(3) y | EC | 172Lu | 0+ | ||||||||||||
172mHf | 2005.58(11) keV | 163(3) ns | (8−) | ||||||||||||||||
173Hf | 72 | 101 | 172.94051(3) | 23.6(1) h | β+ | 173Lu | 1/2− | ||||||||||||
174Hf[n 9] | 72 | 102 | 173.940046(3) | 2.0(4)×1015 y | α | 170Yb | 0+ | 0.0016(1) | 0.001619–0.001621 | ||||||||||
174m1Hf | 1549.3 keV | 138(4) ns | (6+) | ||||||||||||||||
174m2Hf | 1797.5(20) keV | 2.39(4) μs | (8−) | ||||||||||||||||
174m3Hf | 3311.7 keV | 3.7(2) μs | (14+) | ||||||||||||||||
175Hf | 72 | 103 | 174.941509(3) | 70(2) d | β+ | 175Lu | 5/2− | ||||||||||||
176Hf[n 10] | 72 | 104 | 175.9414086(24) | Observationally Stable[n 11] | 0+ | 0.0526(7) | 0.05206–0.05271 | ||||||||||||
177Hf | 72 | 105 | 176.9432207(23) | Observationally Stable[n 12] | 7/2− | 0.1860(9) | 0.18593–0.18606 | ||||||||||||
177m1Hf | 1315.4504(8) keV | 1.09(5) s | 23/2+ | ||||||||||||||||
177m2Hf | 1342.38(20) keV | 55.9(12) μs | (19/2−) | ||||||||||||||||
177m3Hf | 2740.02(15) keV | 51.4(5) min | 37/2− | ||||||||||||||||
178Hf | 72 | 106 | 177.9436988(23) | Observationally Stable[n 13] | 0+ | 0.2728(7) | 0.27278–0.27297 | ||||||||||||
178m1Hf | 1147.423(5) keV | 4.0(2) s | 8− | ||||||||||||||||
178m2Hf | 2445.69(11) keV | 31(1) y | 16+ | ||||||||||||||||
178m3Hf | 2573.5(5) keV | 68(2) μs | (14−) | ||||||||||||||||
179Hf | 72 | 107 | 178.9458161(23) | Observationally Stable[n 14] | 9/2+ | 0.1362(2) | 0.13619–0.1363 | ||||||||||||
179m1Hf | 375.0367(25) keV | 18.67(4) s | 1/2− | ||||||||||||||||
179m2Hf | 1105.84(19) keV | 25.05(25) d | 25/2− | ||||||||||||||||
180Hf | 72 | 108 | 179.9465500(23) | Observationally Stable[n 15] | 0+ | 0.3508(16) | 0.35076–0.351 | ||||||||||||
180m1Hf | 1141.48(4) keV | 5.47(4) h | 8− | ||||||||||||||||
180m2Hf | 1374.15(4) keV | 0.57(2) μs | (4−) | ||||||||||||||||
180m3Hf | 2425.8(10) keV | 15(5) μs | (10+) | ||||||||||||||||
180m4Hf | 2486.3(9) keV | 10(1) μs | 12+ | ||||||||||||||||
180m5Hf | 2538.3(12) keV | >10 μs | (14+) | ||||||||||||||||
180m6Hf | 3599.3(18) keV | 90(10) μs | (18−) | ||||||||||||||||
181Hf | 72 | 109 | 180.9491012(23) | 42.39(6) d | β− | 181Ta | 1/2− | ||||||||||||
181m1Hf | 595(3) keV | 80(5) μs | (9/2+) | ||||||||||||||||
181m2Hf | 1040(10) keV | ~100 μs | (17/2+) | ||||||||||||||||
181m3Hf | 1738(10) keV | 1.5(5) ms | (27/2−) | ||||||||||||||||
182Hf | 72 | 110 | 181.950554(7) | 8.90(9)×106 y | β− | 182Ta | 0+ | ||||||||||||
182mHf | 1172.88(18) keV | 61.5(15) min | β− (58%) | 182Ta | 8− | ||||||||||||||
IT (42%) | 182Hf | ||||||||||||||||||
183Hf | 72 | 111 | 182.95353(3) | 1.067(17) h | β− | 183Ta | (3/2−) | ||||||||||||
184Hf | 72 | 112 | 183.95545(4) | 4.12(5) h | β− | 184Ta | 0+ | ||||||||||||
184mHf | 1272.4(4) keV | 48(10) s | β− | 184Ta | 8− | ||||||||||||||
185Hf | 72 | 113 | 184.95882(21)# | 3.5(6) min | β− | 185Ta | 3/2−# | ||||||||||||
186Hf | 72 | 114 | 185.96089(32)# | 2.6(12) min | β− | 186Ta | 0+ | ||||||||||||
187Hf | 72 | 115 | 186.96459(43)# | 30# s [>300 ns] | |||||||||||||||
188Hf | 72 | 116 | 187.96685(54)# | 20# s [>300 ns] | 0+ | ||||||||||||||
This table header & footer: |
- ^ mHf – 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.
- ^ a b c # – 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 symbol as daughter – Daughter product is stable.
- ^ ( ) spin value – Indicates spin with weak assignment arguments.
- ^ primordial radionuclide
- ^ Used in lutetium-hafnium dating
- ^ Believed to undergo α decay to 172Yb
- ^ Believed to undergo α decay to 173Yb
- ^ Believed to undergo α decay to 174Yb
- ^ Believed to undergo α decay to 175Yb
- ^ Believed to undergo α decay to 176Yb
References[]
- ^ "Standard Atomic Weights: Hafnium". CIAAW. 2019.
- ^ Meija, Juris; 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.
- 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. Lay summary.
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- 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.
Categories:
- Isotopes of hafnium
- Hafnium
- Lists of isotopes by element