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Lanthanum

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Lanthanum

Lanthanum is a chemical element; it has symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. It is the first and the prototype of the lanthanide series, a group of 15 similar elements between lanthanum and lutetium in the periodic table. Lanthanum is traditionally counted among the rare earth elements. Like most other rare earth elements, its usual oxidation state is +3, although some compounds are known with an oxidation state of +2. Lanthanum has no biological role in humans but is used by some bacteria. It is not particularly toxic to humans but does show some antimicrobial activity. Lanthanum usually occurs together with cerium and the other rare earth elements. Lanthanum was first found by the Swedish chemist Carl Gustaf Mosander in 1839 as an impurity in cerium nitrate – hence the name lanthanum, from the ancient Greek λανθάνειν (lanthanein), meaning 'to lie hidden'. Although it is classified as a rare earth element, lanthanum is the 28th most abundant element in the Earth's crust, almost three times as abundant as lead. In minerals such as monazite and bastnäsite, lanthanum composes about a quarter of the lanthanide content. It is extracted from those minerals by a process of such complexity that pure lanthanum metal was not isolated until 1923. Lanthanum compounds have numerous applications including catalysts, additives in glass, carbon arc lamps for studio lights and projectors, ignition elements in lighters and torches, electron cathodes, scintillators, and gas tungsten arc welding electrodes. Lanthanum carbonate is used as a phosphate binder to treat high levels of phosphate in the blood accompanied by kidney failure.

Infobox

Pronunciation
/ˈlænθənəm/ ⓘ (LAN-thə-nəm)
Appearance
silvery white
Atomic number (Z)
57
Group
f-block groups (no number)
Period
period 6
Block
f-block
Electron configuration
[Xe] 5d1 6s2
Electrons per shell
2, 8, 18, 18, 9, 2
Phase at STP
solid
Melting point
1193 K (920 °C, 1688 °F)
Boiling point
3737 K (3464 °C, 6267 °F)
Density (at 20° C)
6.145 g/cm3
when liquid (at m.p.)
5.94 g/cm3
Heat of fusion
6.20 kJ/mol
Heat of vaporization
400 kJ/mol
Molar heat capacity
27.11 J/(mol·K)
P (Pa)
Vapor pressure (extrapolated) P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2005 2208 2458 2772 3178 3726
at T (K)
2005
Oxidation states
common: 3 0, 1, 2
Electronegativity
Pauling scale: 1.10
Ionization energies
1st: 538.1 kJ/mol 2nd: 1067 kJ/mol 3rd: 1850.3 kJ/mol
Atomic radius
empirical: 187 pm
Covalent radius
207±8 pm
Natural occurrence
primordial
Crystal structure
α form: double hexagonal close-packed (dhcp) (hP4)
Lattice constants
a = 0.37742 nmc = 1.2171 nm (at 20 °C)
Thermal expansion
5.1×10−6/K (at 20 °C)[a]
Thermal conductivity
13.4 W/(m⋅K)
Electrical resistivity
α, poly: 615 nΩ⋅m (at r.t.)
Magnetic ordering
paramagnetic
Molar magnetic susceptibility
118.0×10−6 cm3/mol (298 K)
Young's modulus
α form: 36.6 GPa
Shear modulus
α form: 14.3 GPa
Bulk modulus
α form: 27.9 GPa
Speed of sound thin rod
2475 m/s (at 20 °C)
Poisson ratio
α form: 0.280
Mohs hardness
2.5
Vickers hardness
360–1750 MPa
Brinell hardness
350–400 MPa
CAS Number
7439-91-0
Naming
from the Greek λανθάνειν, "to lie hidden", for 'hiding' in cerite
Discovery
Carl Gustaf Mosander (1838)
Main isotopes
mw- body Main isotopes Decay Isotope abun­dance half-life (t1/2) mode pro­duct 137La synth 6×104 y ε 137Ba 138La 0.0890% 1.03×1011 y β 138Ba β− 138Ce 139La 99.9% stable 140La synth 40.289 h β− 140Ce
137La
synth
138La
0.0890%
139La
99.9%
140La
synth

Tables

at T (K)
at T (K)
P (Pa)
at T (K)
1
2005
10
2208
100
2458
1 k
2772
10 k
3178
100 k
3726
P (Pa)
1
10
100
1 k
10 k
100 k
at T (K)
2005
2208
2458
2772
3178
3726
mw- Isotope
mw- Isotope
Main isotopes
mw- Isotope
Main isotopes
abun­dance
Main isotopes
half-life (t1/2)
Decay
mode
Decay
pro­duct
137La
137La
Main isotopes
137La
Main isotopes
synth
Main isotopes
6×104 y
Decay
ε
Decay
137Ba
138La
138La
Main isotopes
138La
Main isotopes
0.0890%
Main isotopes
1.03×1011 y
Decay
β+
Decay
138Ba
β−
β−
Main isotopes
β−
Main isotopes
138Ce
139La
139La
Main isotopes
139La
Main isotopes
99.9%
Main isotopes
stable
140La
140La
Main isotopes
140La
Main isotopes
synth
Main isotopes
40.289 h
Decay
β−
Decay
140Ce
Main isotopes
Decay
mw- Isotope
abun­dance
half-life (t1/2)
mode
pro­duct
137La
synth
6×104 y
ε
137Ba
138La
0.0890%
1.03×1011 y
β+
138Ba
β−
138Ce
139La
99.9%
stable
140La
synth
40.289 h
β−
140Ce

References

  1. The thermal expansion of α-La is anisotropic: the parameters (at 20 °C) for each crystal axis are αa = 2.9×10−6/K, αc =
  2. From Berzelius (1839a), p. 356: "L'oxide de cérium, extrait de la cérite par la procédé ordinaire, contient à peu près
  3. "Standard Atomic Weights: Lanthanum"
    https://www.ciaaw.org/lanthanum.htm
  4. Pure and Applied Chemistry
    https://www.degruyter.com/document/doi/10.1515/pac-2019-0603/html
  5. Selected Values of the Crystallographic Properties of Elements
  6. Chem. Soc. Rev
    https://doi.org/10.1039%2FCS9932200017
  7. Nature Communications
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8578558
  8. Chemistry of the Elements
    https://doi.org/10.1016%2FC2009-0-30414-6
  9. CRC Handbook of Chemistry and Physics
    https://web.archive.org/web/20110303222309/http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elementmagn.pdf
  10. CRC, Handbook of Chemistry and Physics
  11. Chinese Physics C
    https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf
  12. Webmineral
    http://webmineral.com/data/Monazite-(Ce).shtml
  13. Pure and Applied Chemistry
    http://www.iupac.org/publications/pac/1988/pdf/6003x0431.pdf
  14. Quantum Mechanics: Non-relativistic theory
  15. Journal of Chemical Education
    https://ui.adsabs.harvard.edu/abs/1982JChEd..59..634J
  16. Foundations of Chemistry
    https://link.springer.com/article/10.1007/s10698-015-9216-1
  17. Chemistry International
    https://doi.org/10.1515%2Fci-2021-0115
  18. Greenwood & Earnshaw (1984), p. 1106
  19. Handbook of Inorganic Chemical Compounds
    https://books.google.com/books?id=Xqj-TTzkvTEC&pg=PA243
  20. Angewandte Chemie
    https://ui.adsabs.harvard.edu/abs/2008AngCh.120.1510H
  21. Proceedings of the Physical Society
    https://ui.adsabs.harvard.edu/abs/1928PPS....41..520J
  22. Introduction to Magnetic Materials
  23. Festkörper Probleme (plenary lecture)
    https://doi.org/10.1007%2FBFb0108579
  24. Inorganic Chemistry
    https://doi.org/10.1021%2Fic102028d
  25. Handbook on the Physics and Chemistry of Rare Earths
  26. Extractive Metallurgy of Rare Earths
  27. American Journal of Physics
    https://ui.adsabs.harvard.edu/abs/1965AmJPh..33..637H
  28. Some comments on the position of lawrencium in the periodic table
    https://web.archive.org/web/20151223091325/http://www.che.uc.edu/jensen/W.%20B.%20Jensen/Reprints/251.%20Lawrencium.pdf
  29. Angewandte Chemie International Edition
    https://doi.org/10.1002%2Fanie.197300121
  30. Greenwood & Earnshaw (1984), p. 1429
  31. CRC Handbook of Chemistry and Physics
  32. The Radiochemistry of the Rare Earths, Scandium, Yttrium, and Actinium
    http://library.lanl.gov/cgi-bin/getfile?rc000021.pdf
  33. Greenwood & Earnshaw (1984), pp. 1105–1107
  34. "Rare-Earth Metal Long Term Air Exposure Test"
    http://www.elementsales.com/re_exp/index.htm
  35. "Chemical reactions of lanthanum"
    https://www.webelements.com/lanthanum/chemistry.html
  36. Greenwood & Earnshaw (1984), p. 1434
  37. Chinese Physics C
    https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf
  38. The Astrophysical Journal
    https://ui.adsabs.harvard.edu/abs/1990ApJ...356..272W
  39. Chinese Physics C
    https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf
  40. Russian Journal of Applied Chemistry
    https://doi.org/10.1134%2FS1070427209120040
  41. Greenwood & Earnshaw (1984), pp. 1107–1108
  42. The Metal-Hydrogen System, Basic Bulk Properties
  43. Greenwood & Earnshaw (1984), pp. 1108–1109
  44. Greenwood & Earnshaw (1984), p. 1110
  45. "The Discovery and Naming of the Rare Earths"
    http://www.vanderkrogt.net/elements/rareearths.php
  46. Greenwood & Earnshaw (1984), p. 1424
  47. The discovery of the elements
    https://archive.org/details/discoveryoftheel002045mbp
  48. The Journal of Chemical Education
    https://ui.adsabs.harvard.edu/abs/1932JChEd...9.1231W
  49. Comptes rendus
    https://archive.org/stream/ComptesRendusAcademieDesSciences0008/ComptesRendusAcadmieDesSciences-Tome008-Janvier-juin1839#page/n361/mode/1up
  50. Philosophical Magazine
    https://web.archive.org/web/20221115194934/https://books.google.com/books?id=dF1KiX7MbSMC&pg=PA390
  51. "Lanthanum - Periodic Table of Elements: Los Alamos National Laboratory"
    https://periodic.lanl.gov/57.shtml?hl=en-US
  52. jlab.org
    http://education.jlab.org/itselemental/index.html
  53. CRC Handbook of Chemistry and Physics
  54. mindat.org
    https://www.mindat.org/
  55. Greenwood & Earnshaw (1984), p. 1103
  56. Greenwood & Earnshaw (1984), pp. 1426–1429
  57. Episodes from the History of the Rare Earth Elements
    https://books.google.com/books?id=EFzuCAAAQBAJ&q=Welsbach+Actinophor+Atzgersdorf&pg=PA122
  58. "Inside the Nickel Metal Hydride Battery"
    https://web.archive.org/web/20090227062546/http://www.cobasys.com/pdf/tutorial/inside_nimh_battery_technology.pdf
  59. Journal of Alloys and Compounds
    https://doi.org/10.1016%2Fj.jallcom.2006.07.012
  60. "As hybrid cars gobble rare metals, shortage looms"
    https://www.reuters.com/article/ousiv/idUSTRE57U02B20090831
  61. Journal of Power Sources
    https://ui.adsabs.harvard.edu/abs/2008JPS...176..547B
  62. "Why Toyota offers 2 battery choices in next Prius"
    https://www.autonews.com/article/20151123/OEM06/311239986/why-toyota-offers-2-battery-choices-in-next-prius
  63. International Journal of Hydrogen Energy
    https://ui.adsabs.harvard.edu/abs/1999IJHE...24..871U
  64. Handbook of Chemistry and Physics
  65. 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 8–11 July 2007, Cincinnati, OH
    https://web.archive.org/web/20110720091007/http://sgc.engin.umich.edu/erps/IEPC_2007/PAPERS/IEPC-2007-078.pdf
  66. Infrared fiber optics
    https://web.archive.org/web/20100802120432/http://irfibers.rutgers.edu/pdf_files/ir_fiber_review.pdf
  67. oilandgas.saint-gobain.com
    https://web.archive.org/web/20110429014149/http://www.oilandgas.saint-gobain.com/uploadedFiles/SGoilandgas/Documents/Detectors/Detectors-BrilLanCe-NxGen-Packaging.pdf
  68. "Rare Earth Elements and Yttrium"
    https://digital.library.unt.edu/ark:/67531/metadc12817/m1/663/?q=%22carbon%20arc%22
  69. Materials Characterization
    https://doi.org/10.1016%2FS1044-5803%2803%2900055-X
  70. Pool Care Basics
    https://books.google.com/books?id=Kr3NCY4GJaAC&pg=PA25
  71. Arc Welding Automation
    https://books.google.com/books?id=H3BgQGdTP_0C
  72. Welding : Principles and applications
    https://web.archive.org/web/20100923150541/http://www.cmc.dk/
  73. Extractive metallurgy of rare earths
    https://books.google.com/books?id=F0Bte_XhzoAC&pg=PA441
  74. American Mineralogist
    http://www.minsocam.org/ammin/AM73/AM73_1111.pdf
  75. "FDA approves Fosrenol(R) in end-stage renal disease (ESRD) patients"
    https://web.archive.org/web/20090426054033/http://www.medicalnewstoday.com/articles/15538.php
  76. Acta Anatomica
    https://doi.org/10.1159%2F000313647
  77. Applied Clay Science
    https://ui.adsabs.harvard.edu/abs/2009ApCS...46..369H
  78. 2019 IEEE Aerospace Conference
    https://doi.org/10.1109%2FAERO.2019.8742136
  79. Bulletin of Experimental Biology and Medicine
    https://doi.org/10.1007%2Fs10517-005-0503-z
  80. Environmental Microbiology
    https://repository.ubn.ru.nl//bitstream/handle/2066/128108/128108.pdf
  81. Sigma-Aldrich
    https://www.sigmaaldrich.com/catalog/product/aldrich/261130
  82. Science of the Total Environment
    https://ui.adsabs.harvard.edu/abs/1994ScTEn.151..249D
  83. The Medical Journal of Australia
    https://doi.org/10.5694%2Fj.1326-5377.1990.tb126334.x
  84. Nature's Building Blocks: An A-Z guide to the elements
  85. Journal of the American Medical Association
    https://jamanetwork.com/journals/jama/fullarticle/2811509
  86. institut-seltene-erden.de
    https://en.institut-seltene-erden.de/seltene-erden-und-metalle/seltene-erden/lanthan/
  87. institut-seltene-erden.de
    https://en.institut-seltene-erden.de/
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