プラセオジム

導入

原子番号: 59
グループ: なし
原子量: 140.90765
期間: 6
CAS番号: 7440-10-0

分類

カルコゲン
ハロゲン
希ガス
ランタノイド元素
アクチノイド元素
希土類元素
プラチナグループメタル
超ウラン
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

In 1841 Mosander extracted the rare earth didymia from lanthana; in 1879, Lecoq de Boisbaudran isolated a new earth, samaria, from didymiaobtained from the mineral samarskite. Six years later, in 1885, von Welsbach separated didymia into two others, praseodymia and neodymia, whichgave salts of different colors. As with other rare earths, compounds of these elements in solution have distinctive sharp spectral absorption bands orlines, some of which are only a few Angstroms wide. The element occurs along with other rare-earth elements in a variety of minerals. Monazite andbastnasite are the two principal commercial sources of the rare-earth metals. Ion-exchange and solvent extraction techniques have led to much easierisolation of the rare earths and the cost has dropped greatly in the past few years. Thirty six isotopes and isomers are now recognized. Praseodymiumcan be prepared by several methods, such as by calcium reduction of the anhydrous chloride of fluoride. Misch metal, used in making cigarette lighters,contains about 5% praseodymium metal. Praseodymium is soft, silvery, malleable, and ductile. It was prepared in relatively pure form in 1931. It issomewhat more resistant to corrosion in air than europium, lanthanum, cerium, or neodymium, but it does develop a green oxide coating that spallsoff when exposed to air. As with other rare-earth metals it should be kept under a light mineral oil or sealed in plastic. The rare-earth oxides, includingPr2O3, are among the most refractory substances known. Along with other rare earths, it is widely used as a core material for carbon arcs used by themotion picture industry for studio lighting and projection. Salts of praseodymium are used to color glasses and enamels; when mixed with certain othermaterials, praseodymium produces an intense and unusually clean yellow color in glass. Didymium glass, of which praseodymium is a component,is a colorant for welder’s goggles. The metal (99.9% pure) is priced at about $2/g. 1

• "tint[s] sunglasses." 2

物理的特性

融点:3*  931 °C = 1204.15 K = 1707.8 °F
沸点:3* 3520 °C = 3793.15 K = 6368 °F
昇華点:3 
三重点:3 
臨界点:3 
密度:4  6.77 g/cm3

* - at 1 atm

電子構成

電子構成:  *[Xe] 6s2 4f3
ブロック: f
最高占有エネルギーレベル: 6
ヴァランス電子: 2

量子数:

n = 4
ℓ = 3
m = -1
ms = +½

ボンディング

電気陰性度 (ポーリングスケール):5 1.13
Electropositivity (ポーリングスケール): 2.87
仕事関数:6 2.7 eV = 4.3254E-19 J

イオン化ポテンシャル   eV 7  kJ/mol  
1 5.473    528.1
イオン化ポテンシャル   eV 7  kJ/mol  
2 10.55    1017.9
3 21.624    2086.4
イオン化ポテンシャル   eV 7  kJ/mol  
4 38.98    3761.0
5 57.53    5550.8

熱化学

比熱: 0.193 J/g°C 8 = 27.195 J/mol°C = 0.046 cal/g°C = 6.500 cal/mol°C
熱伝導率: 12.5 (W/m)/K, 27°C 9
融解熱: 6.89 kJ/mol 10 = 48.9 J/g
気化熱: 296.8 kJ/mol 11 = 2106.3 J/g
物質の状態 生成エンタルピー (ΔHf°)12 エントロピ (S°)12 ギブズ自由エネルギー (ΔGf°)12
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(s) 0 0 17.5 73.22 0 0
(g) 85.0 355.64 45.34 189.70256 76.7 320.9128

同位体

核種 質量 13 人生の半分 13 核スピン 13 結合エネルギー
121Pr 120.95536(75)# 600(300) ms (3/2-) 977.04 MeV
122Pr 121.95181(54)# 500# ms 985.12 MeV
123Pr 122.94596(64)# 800# ms 3/2+# 1,002.50 MeV
124Pr 123.94296(64)# 1.2(2) s 1,010.57 MeV
125Pr 124.93783(43)# 3.3(7) s 3/2+# 1,027.96 MeV
126Pr 125.93531(21)# 3.12(18) s (4,5,6) 1,036.03 MeV
127Pr 126.93083(21)# 4.2(3) s 3/2+# 1,044.10 MeV
128Pr 127.92879(3) 2.84(9) s (3+) 1,061.49 MeV
129Pr 128.92510(3) 32(3) s (11/2-) 1,069.56 MeV
130Pr 129.92359(7) 40.0(4) s (6,7)(+#) 1,077.63 MeV
131Pr 130.92026(6) 1.50(3) min (3/2+) 1,085.70 MeV
132Pr 131.91926(6) 1.49(11) min (2+) 1,103.09 MeV
133Pr 132.916331(13) 6.5(3) min (3/2+) 1,111.16 MeV
134Pr 133.91571(4) ~11 min (5-) 1,119.23 MeV
135Pr 134.913112(13) 24(2) min 3/2(+) 1,127.30 MeV
136Pr 135.912692(13) 13.1(1) min 2+ 1,135.37 MeV
137Pr 136.910705(13) 1.28(3) h 5/2+ 1,143.44 MeV
138Pr 137.910755(15) 1.45(5) min 1+ 1,151.52 MeV
139Pr 138.908938(8) 4.41(4) h 5/2+ 1,168.90 MeV
140Pr 139.909076(7) 3.39(1) min 1+ 1,176.97 MeV
141Pr 140.9076528(26) STABLE 5/2+ 1,185.04 MeV
142Pr 141.9100448(26) 19.12(4) h 2- 1,183.80 MeV
143Pr 142.9108169(28) 13.57(2) d 7/2+ 1,191.87 MeV
144Pr 143.913305(4) 17.28(5) min 0- 1,199.94 MeV
145Pr 144.914512(8) 5.984(10) h 7/2+ 1,208.02 MeV
146Pr 145.91764(7) 24.15(18) min (2)- 1,216.09 MeV
147Pr 146.918996(25) 13.4(4) min (3/2+) 1,224.16 MeV
148Pr 147.922135(28) 2.29(2) min 1- 1,222.91 MeV
149Pr 148.92372(9) 2.26(7) min (5/2+) 1,230.99 MeV
150Pr 149.926673(28) 6.19(16) s (1)- 1,239.06 MeV
151Pr 150.928319(25) 18.90(7) s (3/2)(-#) 1,247.13 MeV
152Pr 151.93150(13) 3.63(12) s 4+ 1,245.88 MeV
153Pr 152.93384(11) 4.28(11) s 5/2-# 1,253.96 MeV
154Pr 153.93752(16) 2.3(1) s (3+,2+) 1,262.03 MeV
155Pr 154.94012(32)# 1# s [>300 ns] 5/2-# 1,260.78 MeV
156Pr 155.94427(43)# 500# ms [>300 ns] 1,268.85 MeV
157Pr 156.94743(43)# 300# ms 5/2-# 1,276.93 MeV
158Pr 157.95198(64)# 200# ms 1,275.68 MeV
159Pr 158.95550(75)# 100# ms 5/2-# 1,283.75 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。 13

豊富

地球 - ソース化合物: phosphates 14
地球 - 海水: 0.00000064 mg/L 15
地球 -  地殻:  9.2 mg/kg = 0.00092% 15
地球 -  合計:  129 ppb 16
マーキュリー(惑星) -  合計:  99 ppb 16
金星 -  合計:  135 ppb 16
コンドライト - 合計: 0.14 (relative to 106 atoms of Si) 17

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:

マガジン:
(1) Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, pp 136-145.

ソース

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:24.
(2) - Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, p 140.
(3) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(4) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(5) - Dean, John A. Lange's Handbook of Chemistry, 11th ed.; McGraw-Hill Book Company: New York, NY, 1973; p 4:8-4:149.
(6) - Speight, James. Lange's Handbook of Chemistry, 16th ed.; McGraw-Hill Professional: Boston, MA, 2004; p 1:132.
(7) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(8) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
(9) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(10) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(11) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(12) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(13) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(14) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965.
(15) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.
(16) - Morgan, John W. and Anders, Edward, Proc. Natl. Acad. Sci. USA 77, 6973-6977 (1980)
(17) - Brownlow, Arthur. Geochemistry; Prentice-Hall, Inc.: Englewood Cliffs, NJ, 1979, pp 15-16.