镅的同位素
| |||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||
镅是人造元素，没有稳定同位素，也无法确认标准原子质量。目前已发现229Am至247Am（231Am除外）共18种同位素，以及未确认的223Am。其中，243Am最稳定，半衰期7350年。
图表
| 符号 | Z | N | 同位素质量（u） [n 1][n 2] |
半衰期 [n 2] |
衰变 方式[1] |
衰变 产物 |
原子核 自旋[n 1] |
|---|---|---|---|---|---|---|---|
| 激发能量[n 1][n 2] | |||||||
| 223Am[n 3] | 95 | 128 | 223.04584(32)# | 10(9) ms | α | 219Np | 9/2–# |
| 229Am | 95 | 134 | 229.04528(11) | 1.8(15) s | α | 225Np | 5/2–# |
| 230Am | 95 | 135 | 230.04603(15)# | 40(9) s | β+ (<70%) | 230Pu | 1–# |
| β+, SF (>30%) | (various) | ||||||
| 232Am | 95 | 137 | 232.04659(32)# | 79(2) s | β+ (98%) | 232Pu | |
| α (2%) | 228Np | ||||||
| β+, SF (.069%) | (various) | ||||||
| 233Am | 95 | 138 | 233.04635(11)# | 3.2(8) min | β+ | 233Pu | |
| α | 229Np | ||||||
| 234Am | 95 | 139 | 234.04781(22)# | 2.32(8) min | β+ (99.95%) | 234Pu | |
| α (.04%) | 230Np | ||||||
| β+, SF (.0066%) | (various) | ||||||
| 235Am | 95 | 140 | 235.04795(13)# | 9.9(5) min | β+ | 235Pu | 5/2−# |
| α （不常见） | 231Np | ||||||
| 236Am | 95 | 141 | 236.04958(11)# | 3.6(1) min | β+ | 236Pu | |
| α | 232Np | ||||||
| 237Am | 95 | 142 | 237.05000(6)# | 73.0(10) min | β+ (99.97%) | 237Pu | 5/2(−) |
| α (.025%) | 233Np | ||||||
| 238Am | 95 | 143 | 238.05198(5) | 98(2) min | β+ | 238Pu | 1+ |
| α (10−4%) | 234Np | ||||||
| 238mAm | 2500(200)# keV | 35(10) µs | |||||
| 239Am | 95 | 144 | 239.0530245(26) | 11.9(1) h | ε (99.99%) | 239Pu | (5/2)− |
| α (.01%) | 235Np | ||||||
| 239mAm | 2500(200) keV | 163(12) ns | (7/2+) | ||||
| 240Am | 95 | 145 | 240.055300(15) | 50.8(3) h | β+ | 240Pu | (3−) |
| α (1.9×10−4%) | 236Np | ||||||
| 241Am[n 4] | 95 | 146 | 241.0568291(20) | 432.2(7) y | α | 237Np | 5/2− |
| CD (7.4×10−10%) | 207Tl, 34Si | ||||||
| SF (4.3×10−10%) | (various) | ||||||
| 241mAm | 2200(100) keV | 1.2(3) µs | |||||
| 242Am | 95 | 147 | 242.0595492(20) | 16.02(2) h | β− (82.7%) | 242Cm | 1− |
| ε (17.3%) | 242Pu | ||||||
| 242m1Am | 48.60(5) keV | 141(2) y | IT (99.54%) | 242Am | 5− | ||
| α (.46%) | 238Np | ||||||
| SF (1.5×10−8%) | (various) | ||||||
| 242m2Am | 2200(80) keV | 14.0(10) ms | (2+,3−) | ||||
| 243Am[n 4] | 95 | 148 | 243.0613811(25) | 7,370(40) y | α | 239Np | 5/2− |
| SF (3.7×10−9%) | (various) | ||||||
| 244Am | 95 | 149 | 244.0642848(22) | 10.1(1) h | β− | 244Cm | (6−)# |
| 244mAm | 86.1(10) keV | 26(1) min | β− (99.96%) | 244Cm | 1+ | ||
| ε (.0361%) | 244Pu | ||||||
| 245Am | 95 | 150 | 245.066452(4) | 2.05(1) h | β− | 245Cm | (5/2)+ |
| 246Am | 95 | 151 | 246.069775(20) | 39(3) min | β− | 246Cm | (7−) |
| 246m1Am | 30(10) keV | 25.0(2) min | β− (99.99%) | 246Cm | 2(−) | ||
| IT (.01%) | 246Am | ||||||
| 246m2Am | ~2000 keV | 73(10) µs | |||||
| 247Am | 95 | 152 | 247.07209(11)# | 23.0(13) min | β− | 247Cm | (5/2)# |
- ^ 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。
- ^ 223Am的实验数据与理论预测相去甚远，因此其发现存疑。[2]
- ^ 4.0 4.1 Most common isotopes
| ← | 同位素列表 | → |
| 钚的同位素 | 镅的同位素 | 锔的同位素 |
参考文献
- ^ Universal Nuclide Chart. nucleonica. [2015-11-03]. （原始内容
存档于2017-02-19）.
- ^ Sun, M. D.; et al. New short-lived isotope 223Np and the absence of the Z = 92 subshell closure near N = 126. Physics Letters B. 2017, 771: 303–308. Bibcode:2017PhLB..771..303S. doi:10.1016/j.physletb.2017.03.074
.
- 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.