锔的同位素
外观
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锔有从233Cm到251Cm共19种同位素以及10种同核异构体,全部都有放射性。其中,247Cm最稳定,半衰期1560万年,是之后所有原子序更高的核素半衰期的至少一万倍。它是R-过程产生的绝种核素。[1][2]锔最稳定的同核异构体则是246mCm,半衰期1.12秒。
图表
[编辑]符号 | Z | N | 同位素质量(u) [n 1][n 2] |
半衰期 [n 1][n 2] |
衰变 方式[3] |
衰变 产物 [n 3] |
原子核 自旋[n 1] |
---|---|---|---|---|---|---|---|
激发能量[n 2] | |||||||
233Cm | 96 | 137 | 233.05077(8) | 1# min | β+ | 233Am | 3/2+# |
α | 229Pu | ||||||
234Cm | 96 | 138 | 234.05016(2) | 51(12) s | β+ | 234Am | 0+ |
α | 230Pu | ||||||
235Cm | 96 | 139 | 235.05143(22)# | 5# min | β+ | 235Am | 5/2+# |
α | 231Pu | ||||||
236Cm | 96 | 140 | 236.05141(22)# | 10# min | β+ | 236Am | 0+ |
α | 232Pu | ||||||
237Cm | 96 | 141 | 237.05290(22)# | 20# min | β+ | 237Am | 5/2+# |
α | 233Pu | ||||||
238Cm | 96 | 142 | 238.05303(4) | 2.4(1) h | ε (90%) | 238Am | 0+ |
α (10%) | 234Pu | ||||||
239Cm | 96 | 143 | 239.05496(11)# | ~2.9 h | β+ (99.9%) | 239Am | (7/2−) |
α (.1%) | 235Pu | ||||||
240Cm | 96 | 144 | 240.0555295(25) | 27(1) d | α (99.5%) | 236Pu | 0+ |
ε (.5%) | 240Am | ||||||
SF (3.9×10−6%) | (various) | ||||||
241Cm | 96 | 145 | 241.0576530(23) | 32.8(2) d | ε (99%) | 241Am | 1/2+ |
α (1%) | 237Pu | ||||||
242Cm[n 4] | 96 | 146 | 242.0588358(20) | 162.8(2) d | α | 238Pu | 0+ |
SF (6.33×10−6%) | (various) | ||||||
CD (10−14%)[n 5] | 208Pb 34Si | ||||||
243Cm | 96 | 147 | 243.0613891(22) | 29.1(1) y | α (99.71%) | 239Pu | 5/2+ |
ε (.29%) | 243Am | ||||||
SF (5.3×10−9%) | (various) | ||||||
243mCm | 87.4(1) keV | 1.08(3) µs | 1/2+ | ||||
244Cm[n 4] | 96 | 148 | 244.0627526(20) | 18.10(2) y | α | 240Pu | 0+ |
SF (1.34×10−4%) | (various) | ||||||
244mCm | 1040.188(12) keV | 34(2) ms | IT | 244Cm | 6+ | ||
245Cm | 96 | 149 | 245.0654912(22) | 8.5(1)×103 y | α | 241Pu | 7/2+ |
SF (6.1×10−7%) | (various) | ||||||
245mCm | 355.90(10) keV | 290(20) ns | 1/2+ | ||||
246Cm | 96 | 150 | 246.0672237(22) | 4.76(4)×103 y | α (99.97%) | 242Pu | 0+ |
SF (.0261%) | (various) | ||||||
246mCm | 1179.66(13) keV | 1.12(0.24) s | IT | 246Cm | 8- | ||
247Cm | 96 | 151 | 247.070354(5) | 1.56(5)×107 y | α | 243Pu | 9/2− |
248Cm | 96 | 152 | 248.072349(5) | 3.48(6)×105 y | α (91.74%) | 244Pu | 0+ |
SF (8.26%) | (various) | ||||||
249Cm | 96 | 153 | 249.075953(5) | 64.15(3) min | β− | 249Bk | 1/2(+) |
249mCm | 48.758(17) keV | 23 µs | (7/2+) | ||||
250Cm | 96 | 154 | 250.078357(12) | 8,300# y | SF (80%)[n 6] | (various) | 0+ |
α (11%) | 246Pu | ||||||
β− (9%) | 250Bk | ||||||
251Cm | 96 | 155 | 251.082285(24) | 16.8(2) min | β− | 251Bk | (1/2+) |
- ^ 1.0 1.1 1.2 画上#号的数据代表没有经过实验的证明,仅为理论推测。
- ^ 2.0 2.1 2.2 用括号括起来的数据代表不确定性。
- ^ 稳定的衰变产物以粗体表示。
- ^ 4.0 4.1 Most common isotopes
- ^ Heaviest known nuclide to undergo cluster decay
- ^ Lightest nuclide to undergo spontaneous fission as the main decay mode
← | 同位素列表 | → |
镅的同位素 | 锔的同位素 | 锫的同位素 |
参考文献
[编辑]- ^ Côté, Benoit; Eichler, Marius; Yagüe López, Andrés; Vassh, Nicole; Mumpower, Matthew R.; Világos, Blanka; Soós, Benjámin; Arcones, Almudena; Sprouse, Trevor M.; Surman, Rebecca; Pignatari, Marco; Pető, Mária K.; Wehmeyer, Benjamin; Rauscher, Thomas; Lugaro, Maria. 129 I and 247 Cm in meteorites constrain the last astrophysical source of solar r-process elements. Science. 26 February 2021, 371 (6532): 945–948. PMID 33632846. S2CID 232050526. arXiv:2006.04833 . doi:10.1126/science.aba1111.
- ^ Davis, A.M.; McKeegan, K.D. Short-Lived Radionuclides and Early Solar System Chronology. Treatise on Geochemistry. 2014: 383. ISBN 9780080983004. doi:10.1016/B978-0-08-095975-7.00113-3.
- ^ Universal Nuclide Chart. nucleonica. [2015-11-03]. (原始内容存档于2017-02-19).
- Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
- Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties (页面存档备份,存于互联网档案馆), Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (页面存档备份,存于互联网档案馆) (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.