介绍

原子数: 57
组: 3 or III B
原子量: 138.9055
期: 6
CAS号码: 7439-91-0

分类

金属
非金属
非金属
碱金属
碱土金属
过渡金属
硫族
卤素
惰性气体
镧系元素

稀土元素
铂族金属
超铀
没有稳定的同位素
固体
液体
加油站
固体 (预料到的)

描述 • 用途/功能

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

物理性能

熔点:5*  918 °C = 1191.15 K = 1684.4 °F
沸点:5* 3464 °C = 3737.15 K = 6267.2 °F
升华点:5 
三相点:5 
临界点:5 
密度:6  6.15 g/cm3

* - at 1 atm

电子组态

电子组态:  *[Xe] 6s2 4f1
块: d
最高占据能级: 6
价电子: 

量子数:

n = 4
ℓ = 3
m = -3
ms = +½

粘接

电负性 (鲍林规模):7 1.10
Electropositivity (鲍林规模): 2.9
电子亲:8 0.47 eV
氧化态: +3
功函数:9 3.40 eV = 5.4468E-19 J

电离能   eV 10  kJ/mol  
1 5.5769    538.1
电离能   eV 10  kJ/mol  
2 11.06    1067.1
3 19.1773    1850.3
电离能   eV 10  kJ/mol  
4 49.95    4819.4
5 61.6    5943.5

热化学

比热: 0.195 J/g°C 11 = 27.087 J/mol°C = 0.047 cal/g°C = 6.474 cal/mol°C
导热系数: 13.5 (W/m)/K, 27°C 12
融合热: 6.2 kJ/mol 13 = 44.6 J/g
汽化热: 414 kJ/mol 14 = 2980.4 J/g
物质状态 生成焓 (ΔHf°)15 熵 (S°)15 吉布斯自由能 (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

同位素

核素  16 半衰期 16 核自旋 16 结合能
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) 稳定 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
值标记#不是纯粹从实验数据得出,但至少部分来自系统的发展趋势。旋转弱任务参数都包含在括号中。 16

反应

丰富

地球 - 来源化合物: phosphates 17
地球 - 海水: 0.0000034 mg/L 18
地球 -  脆皮:  39 mg/kg = 0.0039% 18
地球 -  总:  379 ppb 19
水星(行星) -  总:  291 ppb 19
金星 -  总:  397 ppb 19
球粒陨石 - 总: 0.39 (relative to 106 atoms of Si) 20

化合物

安全信息


材料安全数据表 - ACI Alloys, Inc.

了解更多信息

外部链接:

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

来源

(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.