ランタン

導入

原子番号: 57
グループ: 3 or III B
原子量: 138.9055
期間: 6
CAS番号: 7439-91-0

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

Mosander in 1839 extracted a new earth lanthana, from impure cerium nitrate, and recognized the new element. Lanthanum is found in rare-earthminerals such as cerite, monazite, allanite, and bastnasite. Monazite and bastnasite are principal ores in which lanthanum occurs in percentages upto 25 and 38%, respectively. Misch metal, used in making lighter flints, contains about 25% lanthanum. Lanthanum was isolated in relatively pureform in 1923. Iron-exchange and solvent extraction techniques have led to much easier isolation of the so-called “rare-earth” elements. The availabilityof lanthanum and other rare earths has improved greatly in recent years. The metal can be produced by reducing the anhydrous fluoride with calcium.Lanthanum is silvery white, malleable, ductile, and soft enough to be cut with a knife. It is one of the most reactive of the rare-earth metals. It oxidizesrapidly when exposed to air. Cold water attacks lanthanum slowly, and hot water attacks it much more rapidly. The metal reacts directly with elementalcarbon, nitrogen, boron, selenium, silicon, phosphorus, sulfur, and with halogens. At 310°C, lanthanum changes from a hexagonal to a face-centeredcubic structure, and at 865°C it again transforms into a body-centered cubic structure. Natural lanthanum is mixture of two isotopes, one of which isstable and one of which is radioactive with a very long half-life. Twenty nine other radioactive isotopes are recognized. Rare-earth compoundscontaining lanthanum are extensively used in carbon lighting applications, especially by the motion picture industry for studio lighting and projection.This application consumes about 25% of the rare-earth compounds produced. La2O3 improves the alkali resistance of glass, and is used in makingspecial optical glasses. Small amounts of lanthanum, as an additive, can be used to produce nodular cast iron. There is current interest in hydrogensponge alloys containing lanthanum. These alloys take up to 400 times their own volume of hydrogen gas, and the process is reversible. Heat energyis released every time they do so; therefore these alloys have possibilities in energy conservation systems. Lanthanum and its compounds have a lowto moderate acute toxicity rating; therefore, care should be taken in handling them. The metal costs about $2/g (99.9%). 1

• "The battery in a single Toyota Prius contains more than 20 pounds of the rare earth element lanthanum" 2
• "Night-vision goggles require lanthanum" 3
• "catalyst in refining oil to gasoline" 4

物理的特性

融点:5*  918 °C = 1191.15 K = 1684.4 °F
沸点:5* 3464 °C = 3737.15 K = 6267.2 °F
昇華点:5 
三重点:5 
臨界点:5 
密度:6  6.15 g/cm3

* - at 1 atm

電子構成

電子構成:  *[Xe] 6s2 4f1
ブロック: d
最高占有エネルギーレベル: 6
ヴァランス電子: 

量子数:

n = 4
ℓ = 3
m = -3
ms = +½

ボンディング

電気陰性度 (ポーリングスケール):7 1.10
Electropositivity (ポーリングスケール): 2.9
電子親和力:8 0.47 eV
酸化状態: +3
仕事関数:9 3.40 eV = 5.4468E-19 J

イオン化ポテンシャル   eV 10  kJ/mol  
1 5.5769    538.1
イオン化ポテンシャル   eV 10  kJ/mol  
2 11.06    1067.1
3 19.1773    1850.3
イオン化ポテンシャル   eV 10  kJ/mol  
4 49.95    4819.4
5 61.6    5943.5

熱化学

比熱: 0.195 J/g°C 11 = 27.087 J/mol°C = 0.047 cal/g°C = 6.474 cal/mol°C
熱伝導率: 13.5 (W/m)/K, 27°C 12
融解熱: 6.2 kJ/mol 13 = 44.6 J/g
気化熱: 414 kJ/mol 14 = 2980.4 J/g
物質の状態 生成エンタルピー (ΔHf°)15 エントロピ (S°)15 ギブズ自由エネルギー (ΔGf°)15
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(s) 0 0 13.6 56.9024 0 0
(g) 103.0 430.952 43.56 182.25504 94.07 393.58888

同位体

核種 質量 16 人生の半分 16 核スピン 16 結合エネルギー
117La 116.95007(43)# 23.5(26) ms (3/2+,3/2-) 946.32 MeV
118La 117.94673(32)# 200# ms 963.71 MeV
119La 118.94099(43)# 1# s 11/2-# 971.78 MeV
120La 119.93807(54)# 2.8(2) s 989.17 MeV
121La 120.93301(54)# 5.3(2) s 11/2-# 997.24 MeV
122La 121.93071(32)# 8.6(5) s 1,005.31 MeV
123La 122.92624(21)# 17(3) s 11/2-# 1,022.70 MeV
124La 123.92457(6) 29.21(17) s (7-,8-) 1,030.77 MeV
125La 124.920816(28) 64.8(12) s (11/2-) 1,038.84 MeV
126La 125.91951(10) 54(2) s (5)(+#) 1,056.23 MeV
127La 126.916375(28) 5.1(1) min (11/2-) 1,064.30 MeV
128La 127.91559(6) 5.18(14) min (5+) 1,072.37 MeV
129La 128.912693(22) 11.6(2) min 3/2+ 1,080.44 MeV
130La 129.912369(28) 8.7(1) min 3(+) 1,088.51 MeV
131La 130.91007(3) 59(2) min 3/2+ 1,096.58 MeV
132La 131.91010(4) 4.8(2) h 2- 1,104.65 MeV
133La 132.90822(3) 3.912(8) h 5/2+ 1,122.04 MeV
134La 133.908514(21) 6.45(16) min 1+ 1,130.11 MeV
135La 134.906977(11) 19.5(2) h 5/2+ 1,138.18 MeV
136La 135.90764(6) 9.87(3) min 1+ 1,146.25 MeV
137La 136.906494(14) 6(2)E+4 a 7/2+ 1,154.32 MeV
138La 137.907112(4) 1.02(1)E+11 a 5+ 1,162.40 MeV
139La 138.9063533(26) STABLE 7/2+ 1,170.47 MeV
140La 139.9094776(26) 1.6781(3) d 3- 1,178.54 MeV
141La 140.910962(5) 3.92(3) h (7/2+) 1,177.29 MeV
142La 141.914079(6) 91.1(5) min 2- 1,185.37 MeV
143La 142.916063(17) 14.2(1) min (7/2)+ 1,193.44 MeV
144La 143.91960(5) 40.8(4) s (3-) 1,201.51 MeV
145La 144.92165(10) 24.8(20) s (5/2+) 1,200.27 MeV
146La 145.92579(8) 6.27(10) s 2- 1,208.34 MeV
147La 146.92824(5) 4.015(8) s (5/2+) 1,216.41 MeV
148La 147.93223(6) 1.26(8) s (2-) 1,215.16 MeV
149La 148.93473(34)# 1.05(3) s 5/2+# 1,223.24 MeV
150La 149.93877(43)# 510(30) ms (3+) 1,231.31 MeV
151La 150.94172(43)# 300# ms [>300 ns] 5/2+# 1,230.06 MeV
152La 151.94625(43)# 200# ms [>300 ns] 1,238.13 MeV
153La 152.94962(64)# 150# ms [>300 ns] 5/2+# 1,246.21 MeV
154La 153.95450(64)# 100# ms 1,244.96 MeV
155La 154.95835(86)# 60# ms 5/2+# 1,253.03 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。 16

反応

豊富

地球 - ソース化合物: phosphates 17
地球 - 海水: 0.0000034 mg/L 18
地球 -  地殻:  39 mg/kg = 0.0039% 18
地球 -  合計:  379 ppb 19
マーキュリー(惑星) -  合計:  291 ppb 19
金星 -  合計:  397 ppb 19
コンドライト - 合計: 0.39 (relative to 106 atoms of Si) 20

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 4:17.
(2) - Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, p 138.
(3) - Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, p 140.
(4) - Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, p 143.
(5) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(6) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(7) - Dean, John A. Lange's Handbook of Chemistry, 11th ed.; McGraw-Hill Book Company: New York, NY, 1973; p 4:8-4:149.
(8) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 10:147-10:148.
(9) - Speight, James. Lange's Handbook of Chemistry, 16th ed.; McGraw-Hill Professional: Boston, MA, 2004; p 1:132.
(10) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(11) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
(12) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(13) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(14) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(15) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(16) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(17) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965.
(18) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.
(19) - Morgan, John W. and Anders, Edward, Proc. Natl. Acad. Sci. USA 77, 6973-6977 (1980)
(20) - Brownlow, Arthur. Geochemistry; Prentice-Hall, Inc.: Englewood Cliffs, NJ, 1979, pp 15-16.