導入
グループ: なし
原子量: 252
期間: 7
CAS番号: 7429-92-7
分類
いいえ安定同位体ません
固体
液体
ガス
固体 (予測)
説明 • 用途/機能
Einsteinium, the seventh transuranic element of the actinide series to be discovered, was identified by Ghiorso and co-workers at Berkeley in December 1952 in debris from the first large thermonuclear explosion, which took place in the Pacific in November 1952. The isotope produced was the 20-day 253Es isotope. In 1961, a sufficient amount of einsteinium was produced to permit separation of a macroscopic amount of 253Es. This sample weighed about 0.01 micrograms. A special magnetic-type balance was used in making this determination. 253Es so produced was used to produce mendelevium (Element 101). About 3 micrograms of einsteinium has been produced at Oak Ridge National Laboratories by irradiating for several years kilogram quantities of 239Pu in a reactor to produce 242Pu. This was then fabricated into pellets of plutonium oxide and aluminum powder, and loaded into target rods for an initial 1-year irradiation at the Savannah River Plant, followed by irradiation in a HFIR (High Flux Isotopic Reactor). After 4 months in the HFIR the targets were removed for chemical separation of the einsteinium from californium. Seventeen isotopes and isomers of einsteinium are now recognized. 254Es has the longest half-life (276 days). Tracer studies using 253Es show that einsteinium has chemical properties typical of a heavy trivalent, actinide element. 1
物理的特性
融点:2* 860 °C = 1133.15 K = 1580 °F
電子構成: *[Rn] 7s2 5f11
n = 5
沸点:2*
昇華点:2
三重点:2
臨界点:2
密度: g/cm3
* - at 1 atm
電子構成
ブロック: f
最高占有エネルギーレベル: 7
ヴァランス電子: 2
量子数:
ℓ = 3
mℓ = 0
ms = -½
ボンディング
イオン化ポテンシャル
eV 3
kJ/mol
イオン化ポテンシャル
eV 3
kJ/mol
イオン化ポテンシャル
eV 3
kJ/mol
1
6.42
619.4
同位体
核種
質量 4
人生の半分 4
核スピン 4
結合エネルギー
240Es
240.06892(43)#
1# s
1,803.77 MeV
241Es
241.06854(24)#
10(5) s [8(+6-5) s]
(3/2-)
1,811.84 MeV
242Es
242.06975(35)#
13.5(25) s
1,819.91 MeV
243Es
243.06955(25)#
21(2) s
3/2-#
1,827.99 MeV
244Es
244.07088(20)#
37(4) s
1,826.74 MeV
245Es
245.07132(22)#
1.1(1) min
(3/2-)
1,834.81 MeV
246Es
246.07290(24)#
7.7(5) min
4-#
1,842.88 MeV
247Es
247.07366(3)#
4.55(26) min
7/2+#
1,850.96 MeV
248Es
248.07547(6)#
27(5) min
2-#,0+#
1,859.03 MeV
249Es
249.07641(3)#
102.2(6) min
7/2+
1,867.10 MeV
250Es
250.07861(11)#
8.6(1) h
(6+)
1,875.17 MeV
251Es
251.079992(7)
33(1) h
(3/2-)
1,883.24 MeV
252Es
252.08298(5)
471.7(19) d
(5-)
1,882.00 MeV
253Es
253.0848247(28)
20.47(3) d
7/2+
1,890.07 MeV
254Es
254.088022(5)
275.7(5) d
(7+)
1,898.14 MeV
255Es
255.090273(12)
39.8(12) d
(7/2+)
1,896.90 MeV
256Es
256.09360(11)#
25.4(24) min
(1+,0-)
1,904.97 MeV
257Es
257.09598(44)#
7.7(2) d
7/2+#
1,913.04 MeV
258Es
258.09952(32)#
3# min
1,921.11 MeV
値は、＃は、純粋に実験データから派生しますが、少なくとも部分的に体系的な傾向からしていないとマーク。弱い代入引数は括弧で囲まれていてスピン。 4
豊富
化合物
安全情報
安全データシート - ACI Alloys, Inc.
詳細については
外部リンク:
American Elements
Chemical & Engineering News
Chemical Elements
ChemGlobe
Chemicool
Environmental Chemistry
ソース
(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:10.
(2) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(3) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(4) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(5) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(6) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(7) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).