Isotopes of holmium
Appearance
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Standard atomic weight Ar°(Ho) | |||||||||||||||||||||||||||||||||||||||||||
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Natural holmium (67Ho) contains one observationally stable isotope, 165Ho. The below table lists 36 isotopes spanning 140Ho through 175Ho as well as 33 nuclear isomers. Among the known synthetic radioactive isotopes; the most stable one is 163Ho, with a half-life of 4,570 years. All other radioisotopes have half-lives not greater than 1.117 days in their ground states (although the metastable 166m1Ho has a half-life of about 1,200 years), and most have half-lives under 3 hours.
List of isotopes
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/7b/Holmium_166m_oxide.png/220px-Holmium_166m_oxide.png)
Nuclide [n 1] |
Z | N | Isotopic mass (Da) [n 2][n 3] |
Half-life [n 4] |
Decay mode [n 5] |
Daughter isotope [n 6] |
Spin and parity [n 7][n 4] |
Isotopic abundance | |||||||||||
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Excitation energy[n 4] | |||||||||||||||||||
140Ho | 67 | 73 | 139.96854(54)# | 6(3) ms | 8+# | ||||||||||||||
141Ho | 67 | 74 | 140.96310(54)# | 4.1(3) ms | (7/2−) | ||||||||||||||
141mHo | 66(2) keV | 6.4(8) µs | (1/2+) | ||||||||||||||||
142Ho | 67 | 75 | 141.95977(54)# | 400(100) ms | β+ | 142Dy | (6 to 9) | ||||||||||||
p | 141Dy | ||||||||||||||||||
143Ho | 67 | 76 | 142.95461(43)# | 300# ms [>200 ns] |
β+ | 143Dy | 11/2−# | ||||||||||||
144Ho | 67 | 77 | 143.95148(32)# | 0.7(1) s | β+ | 144Dy | |||||||||||||
β+, p | 143Tb | ||||||||||||||||||
145Ho | 67 | 78 | 144.94720(32)# | 2.4(1) s | β+ | 145Dy | (11/2−) | ||||||||||||
145mHo | 100(100)# keV | 100# ms | 5/2+# | ||||||||||||||||
146Ho | 67 | 79 | 145.94464(21)# | 3.6(3) s | β+ | 146Dy | (10+) | ||||||||||||
β+, p (rare) | 145Tb | ||||||||||||||||||
147Ho | 67 | 80 | 146.94006(3) | 5.8(4) s | β+ | 147Dy | (11/2−) | ||||||||||||
β+, p (rare) | 146Tb | ||||||||||||||||||
148Ho | 67 | 81 | 147.93772(14) | 2.2(11) s | β+ | 148Dy | (1+) | ||||||||||||
148m1Ho | 400(100)# keV | 9.49(12) s | β+ (99.92%) | 148Dy | (6)− | ||||||||||||||
β+, p (.08%) | 147Tb | ||||||||||||||||||
148m2Ho | 690(100)# keV | 2.35(4) ms | (10+) | ||||||||||||||||
149Ho | 67 | 82 | 148.933775(20) | 21.1(2) s | β+ | 149Dy | (11/2−) | ||||||||||||
149m1Ho | 48.80(20) keV | 56(3) s | β+ | 149Dy | (1/2+) | ||||||||||||||
149m2Ho | 7200(350) keV | >=100 ns | |||||||||||||||||
150Ho | 67 | 83 | 149.933496(15) | 76.8(18) s | β+ | 150Dy | 2− | ||||||||||||
150m1Ho | −10(50) keV | 23.3(3) s | β+ | 150Dy | (9)+ | ||||||||||||||
150m2Ho | ~8000 keV | 751 ns | |||||||||||||||||
151Ho | 67 | 84 | 150.931688(13) | 35.2(1) s | β+ (78%) | 151Dy | 11/2(−) | ||||||||||||
α (22%) | 147Tb | ||||||||||||||||||
151mHo | 41.0(2) keV | 47.2(10) s | α (77%) | 147Tb | 1/2(+) | ||||||||||||||
β+ (22%) | 151Dy | ||||||||||||||||||
152Ho | 67 | 85 | 151.931714(15) | 161.8(3) s | β+ (88%) | 152Dy | 2− | ||||||||||||
α (12%) | 148Tb | ||||||||||||||||||
152m1Ho | 160(1) keV | 50.0(4) s | 9+ | ||||||||||||||||
152m2Ho | 3019.59(19) keV | 8.4(3) µs | 19− | ||||||||||||||||
153Ho | 67 | 86 | 152.930199(6) | 2.01(3) min | β+ (99.94%) | 153Dy | 11/2− | ||||||||||||
α (.05%) | 149Tb | ||||||||||||||||||
153m1Ho | 68.7(3) keV | 9.3(5) min | β+ (99.82%) | 153Dy | 1/2+ | ||||||||||||||
α (.18%) | 149Tb | ||||||||||||||||||
153m2Ho | 2772 keV | 229(2) ns | (31/2+) | ||||||||||||||||
154Ho | 67 | 87 | 153.930602(9) | 11.76(19) min | β+ (99.98%) | 154Dy | 2− | ||||||||||||
α (.02%) | 150Tb | ||||||||||||||||||
154mHo | 238(30) keV | 3.10(14) min | β+ (99.99%) | 154Dy | 8+ | ||||||||||||||
α (.001%) | 150Tb | ||||||||||||||||||
IT (rare) | 154Ho | ||||||||||||||||||
155Ho | 67 | 88 | 154.929103(19) | 48(1) min | β+ | 155Dy | 5/2+ | ||||||||||||
155mHo | 141.97(11) keV | 880(80) µs | 11/2− | ||||||||||||||||
156Ho | 67 | 89 | 155.92984(5) | 56(1) min | β+ | 156Dy | 4− | ||||||||||||
156m1Ho | 100(50)# keV | 7.8(3) min | β+ | 156Dy | (9+) | ||||||||||||||
IT | 156Ho | ||||||||||||||||||
156m2Ho | 52.4(5) keV | 9.5(15) s | 1− | ||||||||||||||||
157Ho | 67 | 90 | 156.928256(26) | 12.6(2) min | β+ | 157Dy | 7/2− | ||||||||||||
158Ho | 67 | 91 | 157.928941(29) | 11.3(4) min | β+ (93%) | 158Dy | 5+ | ||||||||||||
α (7%) | 154Tb | ||||||||||||||||||
158m1Ho | 67.200(10) keV | 28(2) min | IT (81%) | 158Ho | 2− | ||||||||||||||
β+ (19%) | 158Dy | ||||||||||||||||||
158m2Ho | 180(70)# keV | 21.3(23) min | (9+) | ||||||||||||||||
159Ho | 67 | 92 | 158.927712(4) | 33.05(11) min | β+ | 159Dy | 7/2− | ||||||||||||
159mHo | 205.91(5) keV | 8.30(8) s | IT | 159Ho | 1/2+ | ||||||||||||||
160Ho | 67 | 93 | 159.928729(16) | 25.6(3) min | β+ | 160Dy | 5+ | ||||||||||||
160m1Ho | 59.98(3) keV | 5.02(5) h | IT (65%) | 160Ho | 2− | ||||||||||||||
β+ (35%) | 160Dy | ||||||||||||||||||
160m2Ho | 197(16) keV | 3 s | (9+) | ||||||||||||||||
161Ho | 67 | 94 | 160.927855(3) | 2.48(5) h | EC | 161Dy | 7/2− | ||||||||||||
161mHo | 211.16(3) keV | 6.76(7) s | IT | 161Ho | 1/2+ | ||||||||||||||
162Ho | 67 | 95 | 161.929096(4) | 15.0(10) min | β+ | 162Dy | 1+ | ||||||||||||
162mHo | 106(7) keV | 67.0(7) min | IT (62%) | 162Ho | 6− | ||||||||||||||
β+ (38%) | 162Dy | ||||||||||||||||||
163Ho | 67 | 96 | 162.9287339(27) | 4570(25) y | EC | 163Dy | 7/2− | ||||||||||||
163mHo | 297.88(7) keV | 1.09(3) s | IT | 163Ho | 1/2+ | ||||||||||||||
164Ho | 67 | 97 | 163.9302335(30) | 29(1) min | EC (60%) | 164Dy | 1+ | ||||||||||||
β− (40%) | 164Er | ||||||||||||||||||
164mHo | 139.77(8) keV | 38.0(10) min [37.5(+15−5) min] |
IT | 164Ho | 6− | ||||||||||||||
165Ho | 67 | 98 | 164.9303221(27) | Observationally Stable[n 8] | 7/2− | 1.0000 | |||||||||||||
166Ho | 67 | 99 | 165.9322842(27) | 26.83(2) h | β− | 166Er | 0− | ||||||||||||
166m1Ho | 5.985(18) keV | 1200(180) y | β− | 166Er | (7)− | ||||||||||||||
166m2Ho | 190.9052(20) keV | 185(15) µs | 3+ | ||||||||||||||||
167Ho | 67 | 100 | 166.933133(6) | 3.003(18) h | β− | 167Er | 7/2− | ||||||||||||
167mHo | 259.34(11) keV | 6.0(10) µs | 3/2+ | ||||||||||||||||
168Ho | 67 | 101 | 167.93552(3) | 2.99(7) min | β− | 168Er | 3+ | ||||||||||||
168m1Ho | 59(1) keV | 132(4) s | IT (99.5%) | 168Ho | (6+) | ||||||||||||||
β− (.5%) | 168Er | ||||||||||||||||||
168m2Ho | 143.4(2) keV | >4 µs | (1)− | ||||||||||||||||
168m3Ho | 192.6(2) keV | 108(11) ns | 1+ | ||||||||||||||||
169Ho | 67 | 102 | 168.936872(22) | 4.72(10) min | β− | 169Er | 7/2− | ||||||||||||
170Ho | 67 | 103 | 169.93962(5) | 2.76(5) min | β− | 170Er | 6+# | ||||||||||||
170mHo | 120(70) keV | 43(2) s | β− | 170Er | (1+) | ||||||||||||||
171Ho | 67 | 104 | 170.94147(64) | 53(2) s | β− | 171Er | 7/2−# | ||||||||||||
172Ho | 67 | 105 | 171.94482(43)# | 25(3) s | β− | 172Er | |||||||||||||
173Ho | 67 | 106 | 172.94729(43)# | 10# s | β− | 173Er | 7/2−# | ||||||||||||
174Ho | 67 | 107 | 173.95115(54)# | 8# s | |||||||||||||||
175Ho | 67 | 108 | 174.95405(64)# | 5# s | 7/2−# | ||||||||||||||
This table header & footer: |
- ^ mHo – 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).
- ^ 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.
- ^ Believed to undergo α decay to 161Tb
References
- ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
- ^ "Standard Atomic Weights: Holmium". CIAAW. 2021.
- ^ 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.
- 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.