鎂的同位素

鎂共有22個已知同位素，質量數介於19-40之間，其中有3個是穩定的，其他都具有放射性。天然存在的鎂同位素有3個，分別是24Mg、25Mg、26Mg，皆為穩定同位素。其他放射性同位素都不出現在自然界中，只有在實驗室製造出來過，且半衰期都很短，非常不穩定，其中最長壽的是28Mg，半衰期為20.915小時。

圖表

|-
| 18Mg
| style="text-align:right" | 12
| style="text-align:right" | 6
| 
| 
| 2p
| 16Ne
| 0+
|
|
|-
| 19Mg
| style="text-align:right" | 12
| style="text-align:right" | 7
| 19.03417(5)
| 5(3) ps
| 2p
| 17Ne
| 1/2−#
|
|
|-
| rowspan=2|20Mg
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 8
| rowspan=2|20.018863(29)
| rowspan=2|90.8(24) ms
|  (97%)
| 20Na
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β+, p (3%)
| 19Ne
|-
| rowspan=3|21Mg
| rowspan=3 style="text-align:right;" | 12
| rowspan=3 style="text-align:right;" | 9
| rowspan=3|21.011713(18)
| rowspan=3|122(2) ms
| β+ (66.9%)
| 21Na
| rowspan=3|(5/2,3/2)+
| rowspan=3|
| rowspan=3|
|-
| β+, p (32.6%)
| 20Ne
|- 
| β+, α (0.5%)
| 17F
|-
| 22Mg
| style="text-align:right" | 12
| style="text-align:right" | 10
| 21.9995738(14)
| 3.8755(12) s
| β+
| 22Na
| 0+
|
|
|-
| 23Mg
| style="text-align:right" | 12
| style="text-align:right" | 11
| 22.9941237(14)
| 11.317(11) s
| β+
| 23Na
| 3/2+
|
|
|-
| 
| style="text-align:right" | 12
| style="text-align:right" | 12
| 23.985041700(14)
| colspan=3 align=center|
| 0+
| 0.78965(49)
| [0.7888, 0.7905]
|-
| 25Mg
| style="text-align:right" | 12
| style="text-align:right" | 13
| 24.98583692(3)
| colspan=3 align=center|穩定
| 5/2+
| 0.10011(13)
| [0.09988, 0.10034]
|-
| 26Mg用于测定太阳系早期历史事件的放射性定年法中
| style="text-align:right" | 12
| style="text-align:right" | 14
| 25.982592929(30)
| colspan=3 align=center|穩定
| 0+
| 0.11025(38)
| [0.1096, 0.1109]
|-
| 27Mg
| style="text-align:right" | 12
| style="text-align:right" | 15
| 26.98434059(5)
| 9.458(12) min
| β−
| 27Al
| 1/2+
|
|
|-
| 28Mg
| style="text-align:right" | 12
| style="text-align:right" | 16
| 27.9838768(22)
| 20.915(9) h
| β−
| 28Al
| 0+
|
|
|-
| 29Mg
| style="text-align:right" | 12
| style="text-align:right" | 17
| 28.988600(15)
| 1.30(12) s
| β−
| 29Al
| 3/2+
|
|
|-
| rowspan=2|30Mg
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 18
| rowspan=2|29.990434(9)
| rowspan=2|335(17) ms
| β− (99.94%)
| 30Al
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β−, n (.06%)
| 29Al
|-
| rowspan=2|31Mg
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 19
| rowspan=2|30.996546(13)
| rowspan=2|230(20) ms
| β− (98.3%)
| 31Al
| rowspan=2|3/2+
| rowspan=2|
| rowspan=2|
|-
| β−, n (1.7%)
| 30Al
|-
| rowspan=2|32Mg
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 20
| rowspan=2|31.998975(19)
| rowspan=2|86(5) ms
| β− (97.6%)
| 32Al
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β−, n (2.4%)
| 31Al
|-
| rowspan=2|33Mg
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 21
| rowspan=2|33.005254(21)
| rowspan=2|90.5(16) ms
| β− (83%)
| 33Al
| rowspan=2|7/2−#
| rowspan=2|
| rowspan=2|
|-
| β−, n (17%)
| 32Al
|-
| rowspan=2|34Mg
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 22
| rowspan=2|34.00946(25)
| rowspan=2|20(10) ms
| β− (>99.9%)
| 34Al
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β−, n (<.1%)
| 33Al
|-
| rowspan=2|35Mg
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 23
| rowspan=2|35.01734(43)#
| rowspan=2|70(40) ms
| β−, n (52%)
| 34Al
| rowspan=2|(7/2−)#
| rowspan=2|
| rowspan=2|
|-
| β− (48%)
| 35Al
|-
| 36Mg
| style="text-align:right" | 12
| style="text-align:right" | 24
| 36.02300(54)#
| 3.9(13) ms
| β−
| 36Al
| 0+
|
|
|-
| rowspan=2|37Mg
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 25
| rowspan=2|37.03140(97)#
| rowspan=2|40# ms [>260 ns]
| β−
| 37Al
| rowspan=2|7/2−#
| rowspan=2|
| rowspan=2|
|-
| β−, n
| 36Al
|-
| 38Mg
| style="text-align:right" | 12
| style="text-align:right" | 26
| 38.03757(54)#
| 1# ms [>260 ns]
|
|
| 0+
|
|
|-
| 39Mg
| style="text-align:right" | 12
| style="text-align:right" | 27
| 39.04677(55)#
| <260 ns
|
|
| 7/2−#
|
|
|-
| 40Mg
| style="text-align:right" | 12
| style="text-align:right" | 28
| 40.05393(97)#
| 1# ms
|
|
| 0+
|
|
|}

 參考文獻 

 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 , Nuc. Phys. A 729, pp. 3-128 (2003).
 National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database  (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.

Mg
Category:镁