Padron:Infobox lanthanum

Lanthanum, ₅₇La

Lanthanum
Bigkas	/ˈlænθənəm/ ​(LAN-thən-əm)
Appearance	silvery white
Standard atomic weight Ar°(La)
	138.90547±0.00007 138.91±0.01 (pinaikli)[1][2]
Lanthanum sa talahanayang peryodiko
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 Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver 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 Gold Mercury (element) Thallium Lead 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 Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson – ↑ La ↓ Ac barium ← lanthanum → cerium
Atomikong bilang (Z)	57
Group	n/a
Period	6
Block	f-block
Electron configuration	[Xe] 5d1 6s2
Electrons per shell	2, 8, 18, 18, 9, 2
Physical properties
Phase at STP	solido
Melting point	1193 K ​(920 °C, ​1688 °F)
Boiling point	3737 K ​(3464 °C, ​6267 °F)
Density (at 20° C)	6.145 g/cm3 [3]
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)
Vapor pressure (extrapolated) P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2005 2208 2458 2772 3178 3726
Atomic properties
Oxidation states	0,[4] +1,[5] +2, +3 (isang matapang na panimulang oksido)
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
Mga linyang espektral ng lanthanum
Other properties
Crystal structure	α form: ​double hexagonal close-packed (dhcp) (hP4)
Lattice constants	a = 0.37742 nm c = 1.2171 nm (at 20 °C)[3]
Thermal expansion	5.1×10−6/K (at 20 °C)[3][a]
Thermal conductivity	13.4 W/(m⋅K)
Electrical resistivity	α, poly: 615 nΩ⋅m (at r.t.)
Magnetic ordering	paramagnetic[6]
Molar magnetic susceptibility	+118.0×10−6 cm3/mol (298 K)[7]
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
History
Discovery	Carl Gustaf Mosander (1838)
Isotopes of lanthanum t b
Main isotopes[8] Decay abun­dance half-life (t1/2) mode pro­duct 137La synth 6×104 y ε 137Ba 138La 0.089% Preview warning: Infobox La isotopes: Abundance percentage not recognised "na=0.089%" cat#% 1.02×1011 y ε 138Ba β− 138Ce 139La 99.911% Preview warning: Infobox La isotopes: Abundance percentage not recognised "na=99.911%" cat#% stable
Kategorya: Lanthanum tingnan usapan baguhin | references

1. ↑ "Standard Atomic Weights: Lanthanum" (sa wikang Ingles). CIAAW. 2005.
2. ↑ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry (sa wikang Ingles). doi:10.1515/pac-2019-0603. ISSN 1365-3075.
3. ↑ ^{3.0 3.1 3.2 3.3} Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
4. ↑ Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017. and Arnold, Polly L.; Petrukhina, Marina A.; Bochenkov, Vladimir E.; Shabatina, Tatyana I.; Zagorskii, Vyacheslav V.; Cloke (2003-12-15). "Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation". Journal of Organometallic Chemistry (sa wikang Ingles). 688 (1–2): 49–55. doi:10.1016/j.jorganchem.2003.08.028.
5. ↑ La(I), Pr(I), Tb(I), Tm(I), and Yb(I) have been observed in MB₈⁻ clusters; see Li, Wan-Lu; Chen, Teng-Teng; Chen, Wei-Jia; Li, Jun; Wang, Lai-Sheng (2021). "Monovalent lanthanide(I) in borozene complexes". Nature Communications (sa wikang Ingles). 12: 6467. doi:10.1038/s41467-021-26785-9.
6. ↑ Lide, D. R., pat. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (ika-86th (na) edisyon). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
7. ↑ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
8. ↑ ^{8.0 8.1} Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

Maling banggit (May <ref> tag na ang grupong "lower-alpha", pero walang nakitang <references group="lower-alpha"/> tag para rito); $2