锎的同位素
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锎是人造元素，没有稳定同位素。它有20种同位素，原子量介于237至256之间，其中半衰期898年的251Cf最稳定。[1]
图表
[编辑]| 符号 | Z | N | 同位素质量（u） [n 1][n 2] |
半衰期 [n 2] |
衰变 方式[2] |
衰变 产物 |
原子核 自旋[n 1] |
|---|---|---|---|---|---|---|---|
| 激发能量[n 2] | |||||||
| 237Cf | 98 | 139 | 237.06207(54)# | 2.1(3) s | SF | (various) | 5/2+# |
| β+ | 237Bk | ||||||
| α | 233Cm | ||||||
| 238Cf | 98 | 140 | 238.06141(43)# | 21.1(13) ms | SF | (various) | 0+ |
| β+ （不常见） | 238Bk | ||||||
| α （不常见） | 234Cm | ||||||
| 239Cf | 98 | 141 | 239.06242(23)# | 60(30) s [39(+37−12) s] |
α | 235Cm | 5/2+# |
| β+ （不常见） | 239Bk | ||||||
| 240Cf | 98 | 142 | 240.06230(22)# | 1.06(15) min | α (98%) | 236Cm | 0+ |
| SF (2%) | (various) | ||||||
| β+ （不常见） | 240Bk | ||||||
| 241Cf | 98 | 143 | 241.06373(27)# | 3.78(70) min | β+ (75%) | 241Bk | 7/2−# |
| α (25%) | 237Cm | ||||||
| 242Cf | 98 | 144 | 242.06370(4) | 3.49(15) min | α (80%) | 238Cm | 0+ |
| β+ (20%) | 242Bk | ||||||
| SF (.014%) | (various) | ||||||
| 243Cf | 98 | 145 | 243.06543(15)# | 10.7(5) min | β+ (86%) | 243Bk | (1/2+) |
| α (14%) | 239Cm | ||||||
| 244Cf | 98 | 146 | 244.066001(3) | 19.4(6) min | α (99%) | 240Cm | 0+ |
| ε (1%) | 244Bk | ||||||
| 245Cf | 98 | 147 | 245.068049(3) | 45.0(15) min | β+ (64%) | 245Bk | (5/2+) |
| α (36%) | 241Cm | ||||||
| 246Cf | 98 | 148 | 246.0688053(22) | 35.7(5) h | α | 242Cm | 0+ |
| ε (5×10−4%) | 246Bk | ||||||
| SF (2×10−4%) | (various) | ||||||
| 247Cf | 98 | 149 | 247.071001(9) | 3.11(3) h | ε (99.96%) | 247Bk | (7/2+)# |
| α (.04%) | 243Cm | ||||||
| 248Cf | 98 | 150 | 248.072185(6) | 333.5(28) d | α (99.99%) | 244Cm | 0+ |
| SF (.0029%) | (various) | ||||||
| 249Cf | 98 | 151 | 249.0748535(24) | 351(2) y | α | 245Cm | 9/2− |
| SF (5×10−7%) | (various) | ||||||
| 249mCf | 144.98(5) keV | 45(5) µs | 5/2+ | ||||
| 250Cf | 98 | 152 | 250.0764061(22) | 13.08(9) y | α (99.92%) | 246Cm | 0+ |
| SF (.077%) | (various) | ||||||
| 251Cf[n 3] | 98 | 153 | 251.079587(5) | 900(40) y | α | 247Cm | 1/2+ |
| 252Cf[n 4] | 98 | 154 | 252.081626(5) | 2.645(8) y | α (96.9%) | 248Cm | 0+ |
| SF (3.09%)[n 5] | (various) | ||||||
| 253Cf | 98 | 155 | 253.085133(7) | 17.81(8) d | β− (99.69%) | 253Es | (7/2+) |
| α (.31%) | 249Cm | ||||||
| 254Cf | 98 | 156 | 254.087323(13) | 60.5(2) d | SF (99.69%) | (various) | 0+ |
| α (.31%) | 250Cm | ||||||
| 255Cf | 98 | 157 | 255.09105(22)# | 85(18) min | β− (99.99%) | 255Es | (7/2+) |
| SF (.001%) | (various) | ||||||
| α (10−5%) | 251Cm | ||||||
| 256Cf | 98 | 158 | 256.09344(32)# | 12.3(12) min | SF (99%) | (various) | 0+ |
| β− (1%) | 256Es | ||||||
- ^ 1.0 1.1 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。
- ^ High neutron cross-section, tends to absorb neutrons
- ^ Most common isotope
- ^ High neutron emitter, average 3.7 neutrons per fission
| ← | 同位素列表 | → |
| 锫的同位素 | 锎的同位素 | 锿的同位素 |
参考文献
[编辑]- ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. The NUBASE2020 evaluation of nuclear properties (PDF). Chinese Physics C. 2021, 45 (3): 030001. doi:10.1088/1674-1137/abddae.
- ^ 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.