镁的同位素
外观
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标准原子质量 (Ar, 标准) |
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镁共有22个已知同位素,质量数介于19-40之间,其中有3个是稳定的,其他都具有放射性。天然存在的镁同位素有3个,分别是24Mg、25Mg、26Mg,皆为稳定同位素。其他放射性同位素都不出现在自然界中,只有在实验室制造出来过,且半衰期都很短,非常不稳定,其中最长寿的是28Mg,半衰期为20.915小时。
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[2] |
衰变 产物 [n 3] |
原子核 自旋[n 1] |
相对丰度 (莫耳分率)[3][n 2] |
相对丰度 的变化量 (莫耳分率)[4] |
---|---|---|---|---|---|---|---|---|---|
18Mg[5] | 12 | 6 | 2p | 16Ne | 0+ | ||||
19Mg | 12 | 7 | 19.03417(5) | 5(3) ps | 2p | 17Ne | 1/2−# | ||
20Mg | 12 | 8 | 20.018863(29) | 90.8(24) ms | β+ (97%) | 20Na | 0+ | ||
β+, p (3%) | 19Ne | ||||||||
21Mg | 12 | 9 | 21.011713(18) | 122(2) ms | β+ (66.9%) | 21Na | (5/2,3/2)+ | ||
β+, p (32.6%) | 20Ne | ||||||||
β+, α (0.5%) | 17F | ||||||||
22Mg | 12 | 10 | 21.9995738(14) | 3.8755(12) s | β+ | 22Na | 0+ | ||
23Mg | 12 | 11 | 22.9941237(14) | 11.317(11) s | β+ | 23Na | 3/2+ | ||
24 Mg |
12 | 12 | 23.985041700(14) | 稳定 | 0+ | 0.78965(49) | [0.7888, 0.7905] | ||
25Mg | 12 | 13 | 24.98583692(3) | 稳定 | 5/2+ | 0.10011(13) | [0.09988, 0.10034] | ||
26Mg[n 4] | 12 | 14 | 25.982592929(30) | 稳定 | 0+ | 0.11025(38) | [0.1096, 0.1109] | ||
27Mg | 12 | 15 | 26.98434059(5) | 9.458(12) min | β− | 27Al | 1/2+ | ||
28Mg | 12 | 16 | 27.9838768(22) | 20.915(9) h | β− | 28Al | 0+ | ||
29Mg | 12 | 17 | 28.988600(15) | 1.30(12) s | β− | 29Al | 3/2+ | ||
30Mg | 12 | 18 | 29.990434(9) | 335(17) ms | β− (99.94%) | 30Al | 0+ | ||
β−, n (.06%) | 29Al | ||||||||
31Mg | 12 | 19 | 30.996546(13) | 230(20) ms | β− (98.3%) | 31Al | 3/2+ | ||
β−, n (1.7%) | 30Al | ||||||||
32Mg | 12 | 20 | 31.998975(19) | 86(5) ms | β− (97.6%) | 32Al | 0+ | ||
β−, n (2.4%) | 31Al | ||||||||
33Mg | 12 | 21 | 33.005254(21) | 90.5(16) ms | β− (83%) | 33Al | 7/2−# | ||
β−, n (17%) | 32Al | ||||||||
34Mg | 12 | 22 | 34.00946(25) | 20(10) ms | β− (>99.9%) | 34Al | 0+ | ||
β−, n (<.1%) | 33Al | ||||||||
35Mg | 12 | 23 | 35.01734(43)# | 70(40) ms | β−, n (52%) | 34Al | (7/2−)# | ||
β− (48%) | 35Al | ||||||||
36Mg | 12 | 24 | 36.02300(54)# | 3.9(13) ms | β− | 36Al | 0+ | ||
37Mg | 12 | 25 | 37.03140(97)# | 40# ms [>260 ns] | β− | 37Al | 7/2−# | ||
β−, n | 36Al | ||||||||
38Mg | 12 | 26 | 38.03757(54)# | 1# ms [>260 ns] | 0+ | ||||
39Mg | 12 | 27 | 39.04677(55)# | <260 ns | 7/2−# | ||||
40Mg | 12 | 28 | 40.05393(97)# | 1# ms | 0+ |
- ^ 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。
- ^ 用于测定太阳系早期历史事件的放射性定年法中
← | 同位素列表 | → |
钠的同位素 | 镁的同位素 | 铝的同位素 |
参考文献
[编辑]- ^ Meija, Juris; et al. Atomic weights of the elements 2013 (IUPAC Technical Report). Pure and Applied Chemistry. 2016, 88 (3): 265–91. doi:10.1515/pac-2015-0305.
- ^ Universal Nuclide Chart. nucleonica. [2015-09-10]. (原始内容存档于2017-02-19).
- ^ 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.
- ^ Standard Atomic Weights: Magnesium. CIAAW. [2024-06-08].
- ^ Jin, Y.; et al. First observation of the four-proton unbound nucleus 18Mg. Physical Review Letters. 2021, 127 (262502). doi:10.1103/PhysRevLett.127.262502.
- 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.