Lanthanum

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Lanthanum,  57La
Lanthanum-2.jpg
General properties
Appearancesillery white
Staundart atomic wecht (Ar, staundart)138.90547(7)[1]
Lanthanum in the periodic cairt
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
-

La

Ac
bariumlanthanumcerium
Atomic nummer (Z)57
Groupgroup 3
Periodperiod 6
Element category  lanthanide
Blockf-block
Electron confeeguration[Xe] 5d1 6s2
Electrons per shell
2, 8, 18, 18, 9, 2
Pheesical properties
Phase (at STP)solit
Meltin pynt1193 K ​(920 °C, ​1688 °F)
Bylin pynt3737 K ​(3464 °C, ​6267 °F)
Density (near r.t.)6.162 g/cm3
when liquid (at m.p.)5.94 g/cm3
Heat o fusion6.20 kJ/mol
Heat o vapourisation402.1 kJ/mol
Molar heat capacity27.11 J/(mol·K)
Vapour pressur (extrapolated)
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 2005 2208 2458 2772 3178 3726
Atomic properties
Oxidation states3, 2 (strangly basic oxide)
ElectronegativityPauling scale: 1.10
Atomic radiusempirical: 187 pm
Covalent radius207±8 pm
Coloyr lines in a spectral range
Spectral lines o Lanthanum
Miscellanea
Creestal structurhexagonal
Hexagonal creestal structur for lanthanum
Speed o soond thin rod2475 m/s (at 20 °C)
Thermal expansion(r.t.) (α, poly) 12.1 µm/(m·K)
Thermal conductivity13.4 W/(m·K)
Electrical resistivity(r.t.) (α, poly) 615 n Ω·m
Magnetic orderinparamagnetic[2]
Young's modulus(α form) 36.6 GPa
Shear modulus(α form) 14.3 GPa
Bouk modulus(α form) 27.9 GPa
Poisson ratio(α form) 0.280
Mohs haurdness2.5
Vickers haurdness491 MPa
Brinell haurdness363 MPa
CAS Nummer7439-91-0
History
DiskiveryCarl Gustaf Mosander (1838)
Main isotopes o lanthanum
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
137La syn 6×104 y ε 137Ba
138La 0.090% 1.05×1011 y ε 138Ba
β 138Ce
139La 99.910% - (SF)
Decay modes in parentheses are predicted, but hisna yet been observed
| references | in Wikidata

Lanthanum is a chemical element wi the seembol La an atomic nummer 57. Lanthanum is a siller white metallic element an is the first element o the lanthanide series. It is foond in some rare-yird minerals, uisually in combination wi cerium an ither rare yird elements. Lanthanum is a malleable, ductile, an saft metal that oxidises rapidly whan exposed tae air. It is produced frae the minerals monazite an bastnäsite uisin a complex multistage extraction process. Lanthanum compoonds hae hantle applications as catalysts, additives in gless, carbon lichtin for studio lichtin an projection, igneetion elements in lichters an torches, electron cathodes, scintillators, an ithers. Lanthanum carbonate (La2(CO3)3) haes been approved as a medicine for treatin renal failur.

References[eedit | eedit soorce]

  1. Meija, J.; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
  2. Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics (PDF). CRC press. 2000. ISBN 0849304814.