Isotopes of thulium
Naturally occurring thulium (69Tm) is composed of one stable isotope, 169Tm (100% natural abundance). Thirty-six radioisotopes have been characterized, with the most stable being 171Tm with a half-life of 1.92 years, 170Tm with a half-life of 128.6 days, 168Tm with a half-life of 93.1 days, and 167Tm with a half-life of 9.25 days. All of the remaining radioactive isotopes have half-lives that are less than 64 hours, and the majority of these have half-lives that are less than 2 minutes. This element also has 26 meta states, with the most stable being 164mTm (t1/2 5.1 minutes), 160mTm (t1/2 74.5 seconds) and 155mTm (t1/2 45 seconds).
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Standard atomic weight Ar°(Tm) | ||||||||||||||||||||||||||||||||||||
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The isotopes of thulium range in atomic weight from 143.97 u (144Tm) to 178.95534 u (179Tm). The primary decay mode before the most abundant stable isotope, 169Tm, is electron capture, and the primary mode after is beta emission. The primary decay products before 169Tm are erbium isotopes, and the primary products after are ytterbium isotopes. All isotopes of thulium are either radioactive or, in the case of 169Tm, observationally stable, meaning that 169Tm is 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] |
Decay mode [n 5] |
Daughter isotope [n 6] |
Spin and parity [n 7][n 4] |
Natural abundance (mole fraction) | |||||||||||
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Excitation energy[n 4] | Normal proportion | Range of variation | |||||||||||||||||
144Tm[4] | 69 | 75 | 1.9+1.2 −0.5 μs |
p | 143Er | (10+) | |||||||||||||
145Tm | 69 | 76 | 144.97007(43)# | 3.1(3) μs | p | 144Er | (11/2−) | ||||||||||||
146Tm | 69 | 77 | 145.96643(43)# | 240(30) ms | p | 145Er | (6−) | ||||||||||||
β+ (rare) | 146Er | ||||||||||||||||||
146mTm | 71(6) keV | 72(23) ms | p | 145Er | (10+) | ||||||||||||||
β+ (rare) | 146Er | ||||||||||||||||||
147Tm | 69 | 78 | 146.96096(32)# | 0.58(3) s | β+ (85%) | 147Er | 11/2− | ||||||||||||
p (15%) | 146Er | ||||||||||||||||||
147mTm | 60(5) keV | 360(40) μs | 3/2+ | ||||||||||||||||
148Tm | 69 | 79 | 147.95784(43)# | 0.7(2) s | β+ | 148Er | (10+) | ||||||||||||
148mTm | 0.7 s | ||||||||||||||||||
149Tm | 69 | 80 | 148.95272(32)# | 0.9(2) s | β+ (99.74%) | 149Er | (11/2−) | ||||||||||||
β+, p (.26%) | 148Ho | ||||||||||||||||||
150Tm | 69 | 81 | 149.94996(21)# | 3# s | β+ | 150Er | (1+) | ||||||||||||
150m1Tm | 140(140)# keV | 2.20(6) s | β+ (98.8%) | 150Er | (6−) | ||||||||||||||
β+, p (1.2%) | 149Ho | ||||||||||||||||||
150m2Tm | 810(140)# keV | 5.2(3) ms | (10+) | ||||||||||||||||
151Tm | 69 | 82 | 150.945483(22) | 4.17(10) s | β+ | 151Er | (11/2−) | ||||||||||||
151m1Tm | 92(7) keV | 6.6(14) s | β+ | 151Er | (1/2+) | ||||||||||||||
151m2Tm | 2655.67(22) keV | 451(24) ns | (27/2−) | ||||||||||||||||
152Tm | 69 | 83 | 151.94442(8) | 8.0(10) s | β+ | 152Er | (2#)− | ||||||||||||
152m1Tm | 100(80)# keV | 5.2(6) s | β+ | 152Er | (9)+ | ||||||||||||||
152m2Tm | 2555.05(19)+X keV | 294(12) ns | (17+) | ||||||||||||||||
153Tm | 69 | 84 | 152.942012(20) | 1.48(1) s | α (91%) | 149Ho | (11/2−) | ||||||||||||
β+ (9%) | 153Er | ||||||||||||||||||
153mTm | 43.2(2) keV | 2.5(2) s | α (92%) | 149Ho | (1/2+) | ||||||||||||||
β+ (8%) | 153Er | ||||||||||||||||||
154Tm | 69 | 85 | 153.941568(15) | 8.1(3) s | β+ (56%) | 154Er | (2−) | ||||||||||||
α (44%) | 150Ho | ||||||||||||||||||
154mTm | 70(50) keV | 3.30(7) s | α (90%) | 150Ho | (9+) | ||||||||||||||
β+ (10%) | 154Er | ||||||||||||||||||
155Tm | 69 | 86 | 154.939199(14) | 21.6(2) s | β+ (98.1%) | 155Er | (11/2−) | ||||||||||||
α (1.9%) | 151Ho | ||||||||||||||||||
155mTm | 41(6) keV | 45(3) s | β+ (92%) | 155Er | (1/2+) | ||||||||||||||
α (8%) | 151Ho | ||||||||||||||||||
156Tm | 69 | 87 | 155.938980(17) | 83.8(18) s | β+ (99.93%) | 156Er | 2− | ||||||||||||
α (.064%) | 152Er | ||||||||||||||||||
156mTm | 203.6(5) keV | ~400 ns | (11−) | ||||||||||||||||
157Tm | 69 | 88 | 156.93697(3) | 3.63(9) min | β+ | 157Er | 1/2+ | ||||||||||||
158Tm | 69 | 89 | 157.936980(27) | 3.98(6) min | β+ | 158Er | 2− | ||||||||||||
158mTm | 50(100)# keV | ~20 ns | (5+) | ||||||||||||||||
159Tm | 69 | 90 | 158.93498(3) | 9.13(16) min | β+ | 159Er | 5/2+ | ||||||||||||
160Tm | 69 | 91 | 159.93526(4) | 9.4(3) min | β+ | 160Er | 1− | ||||||||||||
160m1Tm | 70(20) keV | 74.5(15) s | IT (85%) | 160Tm | 5(+#) | ||||||||||||||
β+ (15%) | 160Er | ||||||||||||||||||
160m2Tm | 98.2+X keV | ~200 ns | (8) | ||||||||||||||||
161Tm | 69 | 92 | 160.93355(3) | 30.2(8) min | β+ | 161Er | 7/2+ | ||||||||||||
161m1Tm | 7.4(2) keV | 5# min | 1/2+ | ||||||||||||||||
161m2Tm | 78.20(3) keV | 110(3) ns | 7/2− | ||||||||||||||||
162Tm | 69 | 93 | 161.933995(28) | 21.70(19) min | β+ | 162Er | 1− | ||||||||||||
162mTm | 130(40) keV | 24.3(17) s | IT (82%) | 162Tm | 5+ | ||||||||||||||
β+ (18%) | 162Er | ||||||||||||||||||
163Tm | 69 | 94 | 162.932651(6) | 1.810(5) h | β+ | 163Er | 1/2+ | ||||||||||||
164Tm | 69 | 95 | 163.93356(3) | 2.0(1) min | β+ | 164Er | 1+ | ||||||||||||
164mTm | 10(6) keV | 5.1(1) min | IT (80%) | 164Tm | 6− | ||||||||||||||
β+ (20%) | 164Er | ||||||||||||||||||
165Tm | 69 | 96 | 164.932435(4) | 30.06(3) h | β+ | 165Er | 1/2+ | ||||||||||||
166Tm | 69 | 97 | 165.933554(13) | 7.70(3) h | β+ | 166Er | 2+ | ||||||||||||
166mTm | 122(8) keV | 340(25) ms | IT | 166Tm | 6− | ||||||||||||||
167Tm | 69 | 98 | 166.9328516(29) | 9.25(2) d | EC | 167Er | 1/2+ | ||||||||||||
167m1Tm | 179.480(19) keV | 1.16(6) μs | (7/2)+ | ||||||||||||||||
167m2Tm | 292.820(20) keV | 0.9(1) μs | 7/2− | ||||||||||||||||
168Tm | 69 | 99 | 167.934173(3) | 93.1(2) d | β+ (99.99%) | 168Er | 3+ | ||||||||||||
β− (.01%) | 168Yb | ||||||||||||||||||
169Tm | 69 | 100 | 168.9342133(27) | Observationally Stable[n 8] | 1/2+ | 1.0000 | |||||||||||||
170Tm | 69 | 101 | 169.9358014(27) | 128.6(3) d | β− (99.86%) | 170Yb | 1− | ||||||||||||
EC (.14%) | 170Er | ||||||||||||||||||
170mTm | 183.197(4) keV | 4.12(13) μs | (3)+ | ||||||||||||||||
171Tm | 69 | 102 | 170.9364294(28) | 1.92(1) y | β− | 171Yb | 1/2+ | ||||||||||||
171mTm | 424.9560(15) keV | 2.60(2) μs | 7/2− | ||||||||||||||||
172Tm | 69 | 103 | 171.938400(6) | 63.6(2) h | β− | 172Yb | 2− | ||||||||||||
173Tm | 69 | 104 | 172.939604(5) | 8.24(8) h | β− | 173Yb | (1/2+) | ||||||||||||
173mTm | 317.73(20) keV | 10(3) μs | (7/2−) | ||||||||||||||||
174Tm | 69 | 105 | 173.94217(5) | 5.4(1) min | β− | 174Yb | (4)− | ||||||||||||
175Tm | 69 | 106 | 174.94384(5) | 15.2(5) min | β− | 175Yb | (1/2+) | ||||||||||||
176Tm | 69 | 107 | 175.94699(11) | 1.85(3) min | β− | 176Yb | (4+) | ||||||||||||
177Tm | 69 | 108 | 176.94904(32)# | 90(6) s | β− | 177Yb | (7/2−) | ||||||||||||
178Tm | 69 | 109 | 177.95264(43)# | 30# s | β− | 178Yb | |||||||||||||
179Tm | 69 | 110 | 178.95534(54)# | 20# s | β− | 179Yb | 1/2+# | ||||||||||||
This table header & footer: |
- mTm – 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).
- # – 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 symbol as daughter – Daughter product is stable.
- ( ) spin value – Indicates spin with weak assignment arguments.
- Believed to undergo α decay to 165Ho
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: Thulium". CIAAW. 2021.
- Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (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.
- Grzywacz, R.; Karny, M.; Rykaczewski, K. P.; Batchelder, J. C.; Bingham, C. R.; Fong, D.; Gross, C. J.; Krolas, W.; Mazzocchi, C.; Piechaczek, A.; Tantawy, M. N.; Winger, J. A.; Zganjar, E. F. (1 September 2005). "Discovery of the new proton emitter 144Tm". The European Physical Journal A. 25 (1): 145–147. Bibcode:2005EPJAS..25..145G. doi:10.1140/epjad/i2005-06-210-2. ISSN 1434-601X. S2CID 122232690.
- 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.