# 錼的同位素[编辑]

主要的錼同位素|

| 同位素
 | 衰變
 |
| --- | --- |
|  | 丰度
 | 半衰期 (*t*1/2) | 方式
 | 能量 （MeV）
 | 產物
 |
| 236Np
 | 人造
 | 1.53×105 年 | ε
 | 0.93
 | 236U
 |
| β− | 0.48
 | 236Pu
 |
| α
 | 5.01
 | 232Pa
 |
| 237Np
 | 痕量
 | 2.144×106 年 | α
 | 4.957
 | 233Pa
 |
| 238Np
 | 人造
 | 2.099 天 | β− | 1.291
 | 238Pu
 |
| 239Np
 | 痕量
 | 2.356 天 | β− | 0.723
 | 239Pu
 |

 |
|

|  |  |
| --- | --- |
| ←U（92） | Pu（94）→ |

 |
|

**錼**只痕量存在于自然界，通常由人工合成制得，因此无法确定标准原子量。镎有从219Np至244Np（不包括221Np）共25种同位素，没有一个是稳定的。最长寿的放射性同位素是237Np，半衰期214.4万年。

## 圖表

| 符號
 | Z
 | N
 | 同位素質量（u）
 | 半衰期
 | 衰變 方式
 | 衰變 產物
 | 原子核 自旋
 | 相對豐度 （莫耳分率）
 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 激發能量
 |
| 225 Np  | 93
 | 132
 | 225.03391(8)
 | 3# ms [>2 µs]
 | α
 | 221Pa
 | 9/2−#
 |  |
| 226 Np  | 93
 | 133
 | 226.03515(10)#
 | 35(10) ms
 | α
 | 222Pa
 |  |  |
| 227 Np  | 93
 | 134
 | 227.03496(8)
 | 510(60) ms
 | α (99.95%)
 | 223Pa
 | 5/2−#
 |  |
| β+ (.05%)
 | 227U
 |
| 228 Np  | 93
 | 135
 | 228.03618(21)#
 | 61.4(14) s
 | β+ (59%)
 | 228U
 |  |  |
| α (41%)
 | 224Pa
 |
| β+, SF (.012%)
 | (various)
 |
| 229 Np  | 93
 | 136
 | 229.03626(9)
 | 4.0(2) min
 | α (51%)
 | 225Pa
 | 5/2+#
 |  |
| β+ (49%)
 | 229U
 |
| 230 Np  | 93
 | 137
 | 230.03783(6)
 | 4.6(3) min
 | β+ (97%)
 | 230U
 |  |  |
| α (3%)
 | 226Pa
 |
| 231 Np  | 93
 | 138
 | 231.03825(5)
 | 48.8(2) min
 | β+ (98%)
 | 231U
 | (5/2)(+#)
 |  |
| α (2%)
 | 227Pa
 |
| 232 Np  | 93
 | 139
 | 232.04011(11)#
 | 14.7(3) min
 | β+ (99.99%)
 | 232U
 | (4+)
 |  |
| α (.003%)
 | 228Pa
 |
| 233 Np  | 93
 | 140
 | 233.04074(5)
 | 36.2(1) min
 | β+ (99.99%)
 | 233U
 | (5/2+)
 |  |
| α (.001%)
 | 229Pa
 |
| 234 Np  | 93
 | 141
 | 234.042895(9)
 | 4.4(1) d
 | β+ | 234U
 | (0+)
 |  |
| 235 Np  | 93
 | 142
 | 235.0440633(21)
 | 396.1(12) d
 | ε
 | 235U | 5/2+
 |  |
| α (.0026%)
 | 231Pa
 |
| 236 Np  | 93
 | 143
 | 236.04657(5)
 | 1.54(6)×105 y
 | ε (87.3%)
 | 236U
 | (6−)
 |  |
| β− (12.5%)
 | 236Pu
 |
| α (.16%)
 | 232Pa
 |
| 236m Np  | 60(50) keV
 | 22.5(4) h
 | ε (52%)
 | 236U
 | 1
 |  |
| β− (48%)
 | 236Pu
 |
| 237 Np  | 93
 | 144
 | 237.0481734(20)
 | 2.144(7)×106 y
 | α
 | 233Pa
 | 5/2+
 | 痕量
 |
| SF (2×10−10%)
 | (various)
 |
| CD (4×10−12%)
 | 207Tl 30Mg
 |
| 238 Np  | 93
 | 145
 | 238.0509464(20)
 | 2.117(2) d
 | β− | 238Pu
 | 2+
 |  |
| 238m Np  | 2300(200)# keV
 | 112(39) ns
 |  |  |  |  |
| 239 Np  | 93
 | 146
 | 239.0529390(22)
 | 2.356(3) d
 | β− | 239Pu
 | 5/2+
 | 痕量
 |
| 240 Np  | 93
 | 147
 | 240.056162(16)
 | 61.9(2) min
 | β− | 240Pu
 | (5+)
 | 痕量
 |
| 240m Np  | 20(15) keV
 | 7.22(2) min
 | β− (99.89%)
 | 240Pu
 | 1(+)
 |  |
| IT (.11%)
 | 240Np
 |
| 241 Np  | 93
 | 148
 | 241.05825(8)
 | 13.9(2) min
 | β− | 241Pu
 | (5/2+)
 |  |
| 242 Np  | 93
 | 149
 | 242.06164(21)
 | 2.2(2) min
 | β− | 242Pu
 | (1+)
 |  |
| 242m Np  | 0(50)# keV
 | 5.5(1) min
 |  |  | 6+#
 |  |
| 243 Np  | 93
 | 150
 | 243.06428(3)#
 | 1.85(15) min
 | β− | 243Pu
 | (5/2−)
 |  |
| 244 Np  | 93
 | 151
 | 244.06785(32)#
 | 2.29(16) min
 | β− | 244Pu
 | (7−)
 |  |

|  |  |  |
| --- | --- | --- |
| ←
 | 同位素列表
 | →
 |
| 鈾的同位素
 | **錼的同位素** | 鈽的同位素
 |

## 参考文獻

* 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 （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.