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Standard atomic weight Ar°(Er) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Naturally occurring erbium (68Er) is composed of six stable isotopes, with 166Er being the most abundant (33.503% natural abundance). Thirty-nine radioisotopes have been characterized with between 74 and 112 neutrons, or 142 to 180 nucleons, with the most stable being 169Er with a half-life of 9.4 days, 172Er with a half-life of 49.3 hours, 160Er with a half-life of 28.58 hours, 165Er with a half-life of 10.36 hours, and 171Er with a half-life of 7.516 hours. All of the remaining radioactive isotopes have half-lives that are less than 3.5 hours, and the majority of these have half-lives that are less than 4 minutes. This element also has numerous meta states, with the most stable being 167mEr (t1/2 2.269 seconds).
The isotopes of erbium range in atomic weight from 141.9723 u (142Er) to 179.9644 u (180Er). The primary decay mode before the most abundant stable isotope, 166Er, is electron capture, and the primary mode after is beta decay. The primary decay products before 166Er are holmium isotopes, and the primary products after are thulium isotopes. All isotopes of erbium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.
List of isotopes
[edit]Nuclide [n 1] |
Z | N | Isotopic mass (Da)[4] [n 2][n 3] |
Half-life[1] [n 4] |
Decay mode[1] [n 5] |
Daughter isotope [n 6] |
Spin and parity[1] [n 7][n 4] |
Natural abundance (mole fraction) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy[n 4] | Normal proportion[1] | Range of variation | |||||||||||||||||
142Er | 68 | 74 | 141.97002(54)# | 10# μs | p | 141Ho | 0+ | ||||||||||||
143Er | 68 | 75 | 142.96655(43)# | 200# ms | β+ | 143Ho | 9/2−# | ||||||||||||
β+, p | 142Dy | ||||||||||||||||||
144Er | 68 | 76 | 143.96070(21)# | 400# ms [>200 ns] | β+ | 144Ho | 0+ | ||||||||||||
145Er | 68 | 77 | 144.95787(22)# | 900(200) ms | β+ | 145Ho | 1/2+# | ||||||||||||
β+, p (rare) | 144Dy | ||||||||||||||||||
145mEr | 205(4)# keV | 1.0(3) s | β+ | 145Ho | (11/2-) | ||||||||||||||
IT (rare) | 145Er | ||||||||||||||||||
β+, p (rare) | 144Dy | ||||||||||||||||||
146Er | 68 | 78 | 145.952418(7) | 1.7(6) s | β+ | 146Ho | 0+ | ||||||||||||
β+, p (rare) | 145Dy | ||||||||||||||||||
147Er | 68 | 79 | 146.94996(4)# | 3.2(1.2) s | β+ | 147Ho | (1/2+) | ||||||||||||
β+, p (rare) | 146Dy | ||||||||||||||||||
147mEr | 100(50)# keV | 1.6(2) s | β+ | 147Ho | (11/2−) | ||||||||||||||
β+, p (rare) | 146Dy | ||||||||||||||||||
148Er | 68 | 80 | 147.944735(11)# | 4.6(2) s | β+ (99.85%) | 148Ho | 0+ | ||||||||||||
β+, p (.15%) | 147Dy | ||||||||||||||||||
148mEr | 2.9132(4) MeV | 13(3) μs | IT | 148Er | (10+) | ||||||||||||||
149Er | 68 | 81 | 148.94231(3) | 4(2) s | β+ (92.8%) | 149Ho | (1/2+) | ||||||||||||
β+, p (7.2%) | 148Dy | ||||||||||||||||||
149m1Er | 741.8(2) keV | 8.9(2) s | β+ (96.5%) | 149Ho | (11/2−) | ||||||||||||||
IT (3.5%) | 149Er | ||||||||||||||||||
β+, p (.18%) | 148Dy | ||||||||||||||||||
149m2Er | 2.6111(3) MeV | 0.61(8) μs | IT | 149Er | (19/2+) | ||||||||||||||
149m3Er | 3.302(7) MeV | 4.8(1) μs | IT | 149Er | (27/2−) | ||||||||||||||
150Er | 68 | 82 | 149.937916(18) | 18.5(7) s | β+ | 150Ho | 0+ | ||||||||||||
150mEr | 2.7965(5) MeV | 2.55(10) μs | IT | 150Er | 10+ | ||||||||||||||
151Er | 68 | 83 | 150.937449(18) | 23.5(20) s | β+ | 151Ho | (7/2−) | ||||||||||||
151m1Er | 2.5860(5) MeV | 580(20) ms | IT (95.3%) | 151Er | (27/2−) | ||||||||||||||
β+ (4.7%) | 151Ho | ||||||||||||||||||
151m2Er | 10.2866(10) MeV | 0.42(5) μs | IT | 151Er | (65/2-, 61/2+) | ||||||||||||||
152Er | 68 | 84 | 151.935050(9) | 10.3(1) s | α (90%) | 148Dy | 0+ | ||||||||||||
β+ (10%) | 152Ho | ||||||||||||||||||
153Er | 68 | 85 | 152.935086(10) | 37.1(2) s | α (53%) | 149Dy | 7/2(−) | ||||||||||||
β+ (47%) | 153Ho | ||||||||||||||||||
153m1Er | 2.7982(10) MeV | 373(9) ns | IT | 153Er | (27/2-) | ||||||||||||||
153m2Er | 5.2481(10) MeV | 248(32) ns | IT | 153Er | (41/2-) | ||||||||||||||
154Er | 68 | 86 | 153.932791(5) | 3.73(9) min | β+ (99.53%) | 154Ho | 0+ | ||||||||||||
α (.47%) | 150Dy | ||||||||||||||||||
155Er | 68 | 87 | 154.933216(7) | 5.3(3) min | β+ (99.978%) | 155Ho | 7/2− | ||||||||||||
α (.022%) | 151Dy | ||||||||||||||||||
156Er | 68 | 88 | 155.931066(26) | 19.5(10) min | β+ | 156Ho | 0+ | ||||||||||||
α (1.2×10−5%) | 152Dy | ||||||||||||||||||
157Er | 68 | 89 | 156.931923(28) | 18.65(10) min | β+ | 157Ho | 3/2− | ||||||||||||
157mEr | 155.4(3) keV | 76(6) ms | IT | 157Er | (9/2+) | ||||||||||||||
158Er | 68 | 90 | 157.929893(27) | 2.29(6) h | EC | 158Ho | 0+ | ||||||||||||
159Er | 68 | 91 | 158.930691(4) | 36(1) min | β+ | 159Ho | 3/2− | ||||||||||||
159m1Er | 182.602(24) keV | 337(14) ns | IT | 159Er | 9/2+ | ||||||||||||||
159m2Er | 429.05(3) keV | 590(60) ns | IT | 159Er | 11/2− | ||||||||||||||
160Er | 68 | 92 | 159.929077(26) | 28.58(9) h | EC | 160Ho | 0+ | ||||||||||||
161Er | 68 | 93 | 160.930004(9) | 3.21(3) h | β+ | 161Ho | 3/2− | ||||||||||||
161mEr | 396.44(4) keV | 7.5(7) μs | IT | 161Er | 11/2− | ||||||||||||||
162Er | 68 | 94 | 161. 9287873(8) | Observationally Stable[n 8] | 0+ | 0.00139(5) | |||||||||||||
162mEr | 2.02601(13) MeV | 88(16) ns | IT | 162Er | (7-) | ||||||||||||||
163Er | 68 | 95 | 162.930040(5) | 75.0(4) min | β+ | 163Ho | 5/2− | ||||||||||||
163mEr | 445.5(6) keV | 580(100) ns | IT | 163Er | (11/2−) | ||||||||||||||
164Er | 68 | 96 | 163.9292077(8) | Observationally Stable[n 9] | 0+ | 0.01601(3) | |||||||||||||
165Er | 68 | 97 | 164.9307335(10) | 10.36(4) h | EC | 165Ho | 5/2− | ||||||||||||
165m1Er | 551.3(6) keV | 250(30)ns | IT | 165Er | 11/2- | ||||||||||||||
165m2Er | 1.8230(6) MeV | 370(40)ns | IT | 165Er | (19/2) | ||||||||||||||
166Er | 68 | 98 | 165.9303011(4) | Observationally Stable[n 10] | 0+ | 0.33503(36) | |||||||||||||
167Er | 68 | 99 | 166.9320562(3) | Observationally Stable[n 11] | 7/2+ | 0.22869(9) | |||||||||||||
167mEr | 207.801(5) keV | 2.269(6) s | IT | 167Er | 1/2− | ||||||||||||||
168Er | 68 | 100 | 167.93237828(28) | Observationally Stable[n 12] | 0+ | 0.26978(18) | |||||||||||||
168mEr | 1.0940383(16) MeV | 109.0(7) ns | IT | 168Er | 4- | ||||||||||||||
169Er | 68 | 101 | 168.9345984(3) | 9.392(18) d | β− | 169Tm | 1/2− | ||||||||||||
169m1Er | 92.05(10) keV | 285(20) ns | IT | 169Er | (5/2-) | ||||||||||||||
169m2Er | 243.69(17) keV | 200(10) ns | IT | 169Er | 7/2+ | ||||||||||||||
170Er | 68 | 102 | 169.9354719(15) | Observationally Stable[n 13] | 0+ | 0.14910(36) | |||||||||||||
171Er | 68 | 103 | 170.93803746(15) | 7.516(2) h | β− | 171Tm | 5/2− | ||||||||||||
171mEr | 198.61(9) keV| | 210(10) ns | IT | 171Er | 1/2− | ||||||||||||||
172Er | 68 | 104 | 171.939363(4) | 49.3(5) h | β− | 172Tm | 0+ | ||||||||||||
172mEr | 1.5009(3) MeV | 579(62) ns | IT | 172Er | (6+) | ||||||||||||||
173Er | 68 | 105 | 172.94240(21)# | 1.434(17) min | β− | 173Tm | (7/2−) | ||||||||||||
174Er | 68 | 106 | 173.94423(32)# | 3.2(2) min | β− | 174Tm | 0+ | ||||||||||||
174mEr | 1.1115(7) MeV | 3.9(3) s | IT | 174Er | 8- | ||||||||||||||
175Er | 68 | 107 | 174.94777(43)# | 1.2(3) min | β− | 175Tm | 9/2+# | ||||||||||||
176Er | 68 | 108 | 175.94994(43)# | 12# s (>300 ns) | β− | 176Tm | 0+ | ||||||||||||
177Er | 68 | 109 | 176.95399(54)# | 8# s (>300 ns) | β− | 177Tm | 1/2−# | ||||||||||||
178Er | 68 | 110 | 177.95678(64)# | 4# s (>300 ns) | β− | 178Tm | 0+ | ||||||||||||
179Er | 68 | 111 | 178.96127(54)# | 3# s (>550 ns) | β− | 179Tm | 3/2−# | ||||||||||||
β−, n | 178Tm | ||||||||||||||||||
180Er | 68 | 112 | 179.96438(54)# | 2# s (>550 ns) | β− | 180Tm | 0+ | ||||||||||||
β−, n | 179Tm | ||||||||||||||||||
This table header & footer: |
- ^ mEr – 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
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 158Dy or β+β+ to 162Dy with a half-life over 140×1012 years
- ^ Believed to undergo α decay to 160Dy or β+β+ to 164Dy
- ^ Believed to undergo α decay to 162Dy
- ^ Believed to undergo α decay to 163Dy
- ^ Believed to undergo α decay to 164Dy
- ^ Believed to undergo α decay to 166Dy or β−β− to 170Yb with a half-life over 410×1015 years
References
[edit]- ^ a b c d e 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: Erbium". CIAAW. 1999.
- ^ 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.
- ^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
- Isotope masses from:
- Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
- Isotopic compositions and standard atomic masses from:
- 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.
- 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.
- 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.
- 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.