鋂是人造元素,沒有穩定同位素,也無法確認標準原子質量。目前已發現229Am至247Am(231Am除外)共18種同位素,以及未確認的223Am。其中,243Am最穩定,半衰期7350年。
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More information 符號, Z ...
符號
|
Z
|
N
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同位素質量(u) [n 1][n 2]
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半衰期 [n 2]
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衰變 方式[1]
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衰變 產物
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原子核 自旋[n 1]
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激發能量[n 1][n 2]
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223Am[n 3]
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95
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128
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223.04584(32)#
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10(9) ms
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α
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219Np
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9/2–#
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229Am
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95
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134
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229.04528(11)
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1.8(15) s
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α
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225Np
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5/2–#
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230Am
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95
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135
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230.04603(15)#
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40(9) s
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β+ (<70%)
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230Pu
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1–#
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β+, SF (>30%)
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(various)
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232Am
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95
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137
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232.04659(32)#
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79(2) s
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β+ (98%)
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232Pu
|
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α (2%)
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228Np
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β+, SF (.069%)
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(various)
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233Am
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95
|
138
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233.04635(11)#
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3.2(8) min
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β+
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233Pu
|
|
α
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229Np
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234Am
|
95
|
139
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234.04781(22)#
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2.32(8) min
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β+ (99.95%)
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234Pu
|
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α (.04%)
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230Np
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β+, SF (.0066%)
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(various)
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235Am
|
95
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140
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235.04795(13)#
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9.9(5) min
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β+
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235Pu
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5/2−#
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α (不常見)
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231Np
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236Am
|
95
|
141
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236.04958(11)#
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3.6(1) min
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β+
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236Pu
|
|
α
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232Np
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237Am
|
95
|
142
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237.05000(6)#
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73.0(10) min
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β+ (99.97%)
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237Pu
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5/2(−)
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α (.025%)
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233Np
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238Am
|
95
|
143
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238.05198(5)
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98(2) min
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β+
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238Pu
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1+
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α (10−4%)
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234Np
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238mAm
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2500(200)# keV
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35(10) µs
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|
|
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239Am
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95
|
144
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239.0530245(26)
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11.9(1) h
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ε (99.99%)
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239Pu
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(5/2)−
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α (.01%)
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235Np
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239mAm
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2500(200) keV
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163(12) ns
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|
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(7/2+)
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240Am
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95
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145
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240.055300(15)
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50.8(3) h
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β+
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240Pu
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(3−)
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α (1.9×10−4%)
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236Np
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241Am[n 4]
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95
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146
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241.0568291(20)
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432.2(7) y
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α
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237Np
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5/2−
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CD (7.4×10−10%)
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207Tl, 34Si
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SF (4.3×10−10%)
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(various)
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241mAm
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2200(100) keV
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1.2(3) µs
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|
|
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242Am
|
95
|
147
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242.0595492(20)
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16.02(2) h
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β− (82.7%)
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242Cm
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1−
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ε (17.3%)
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242Pu
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242m1Am
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48.60(5) keV
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141(2) y
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IT (99.54%)
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242Am
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5−
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α (.46%)
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238Np
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SF (1.5×10−8%)
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(various)
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242m2Am
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2200(80) keV
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14.0(10) ms
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|
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(2+,3−)
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243Am[n 4]
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95
|
148
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243.0613811(25)
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7,370(40) y
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α
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239Np
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5/2−
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SF (3.7×10−9%)
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(various)
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244Am
|
95
|
149
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244.0642848(22)
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10.1(1) h
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β−
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244Cm
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(6−)#
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244mAm
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86.1(10) keV
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26(1) min
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β− (99.96%)
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244Cm
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1+
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ε (.0361%)
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244Pu
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245Am
|
95
|
150
|
245.066452(4)
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2.05(1) h
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β−
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245Cm
|
(5/2)+
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246Am
|
95
|
151
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246.069775(20)
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39(3) min
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β−
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246Cm
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(7−)
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246m1Am
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30(10) keV
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25.0(2) min
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β− (99.99%)
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246Cm
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2(−)
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IT (.01%)
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246Am
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246m2Am
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~2000 keV
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73(10) µs
|
|
|
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247Am
|
95
|
152
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247.07209(11)#
|
23.0(13) min
|
β−
|
247Cm
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(5/2)#
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Close
畫上#號的數據代表沒有經過實驗的証明,僅為理論推測。
223Am的實驗數據與理論預測相去甚遠,因此其發現存疑。[2]
- 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 (頁面存檔備份,存於網際網路檔案館), Nuc. Phys. A 729, pp. 3–128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (頁面存檔備份,存於網際網路檔案館) (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.