Difference between revisions of "Lanthanum"

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'''Lanthanum''' is a rare-earth metal with chemical symbol La, and an atomic weight of 57. Lanthanum is the first element in the [[lanthanide]] series.
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{{Infobox element
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<!-- General properties -->
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|name=Lanthanum
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|symbol=La
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|pronounce=
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|pronounce ref=
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|pronounce comment=
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|pronounce 2=
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|alt name=
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|alt names=
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|allotropes=
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|appearance=Silvery-white
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<!-- Periodic table -->
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|above=[[Yttrium|Y]]
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|below=Ac
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|left=[[Barium]]
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|right=[[Cerium]]
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|number=57
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|atomic mass=138.90547(7)
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|atomic mass 2=
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|atomic mass ref=
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|atomic mass comment=
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|series=
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|series comment=
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|series color=
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|group=3
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|group ref=
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|group comment=
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|period=6
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|period ref=
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|period comment=
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|block=d
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|block ref=
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|block comment=
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|electron configuration=[Xe] 5d<sup>1</sup> 6s<sup>2</sup>
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|electron configuration ref=
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|electron configuration comment=
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|electrons per shell=
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|electrons per shell ref=
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|electrons per shell comment=
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<!-- Physical properties -->
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|physical properties comment=
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|color=Silvery-white
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|phase=Solid
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|phase ref=
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|phase comment=
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|melting point K=1193
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|melting point C=920
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|melting point F=1688
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|melting point ref=
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|melting point comment=
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|boiling point K=3737
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|boiling point C=3464
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|boiling point F=​6267
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|sublimation point K=
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|sublimation point C=
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|sublimation point F=
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|sublimation point comment=
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|density gplstp=
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|density gplstp ref=
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|density gplstp comment=
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|density gpcm3nrt=6.162
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|density gpcm3nrt ref=
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|density gpcm3nrt 3=
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|density gpcm3nrt 3 comment=
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|density gpcm3mp=5.94
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|density gpcm3mp ref=
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|density gpcm3mp comment=
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|density gpcm3bp=
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|density gpcm3bp ref=
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|molar volume=
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|molar volume unit =
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|molar volume comment=
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|triple point K=
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|triple point kPa=
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|triple point ref=
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|triple point K 2=
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|triple point kPa 2=
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|critical point K=
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|critical point MPa=
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|critical point ref=
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|critical point comment=
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|heat fusion=6.20
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|heat fusion ref=
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|heat fusion 2=
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|heat fusion 2 ref=
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|heat fusion 2 comment=
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|heat vaporization=400
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|heat vaporization ref=
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|heat vaporization comment=
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|heat capacity=27.11
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|heat capacity ref=
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|heat capacity comment=
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|heat capacity 2=
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|heat capacity 2 ref=
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|heat capacity 2 comment=
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|vapor pressure 1=2005
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|vapor pressure 10=2208
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|vapor pressure 100=2458
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|vapor pressure 1 k=2772
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|vapor pressure 10 k=3178
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|vapor pressure 100 k=3726
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|vapor pressure ref=
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|vapor pressure 1 2=
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|vapor pressure 10 2=
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|vapor pressure 1 k 2=
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|vapor pressure 10 k 2=
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|vapor pressure 100 k 2=
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|vapor pressure 2 ref=
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|vapor pressure 2 comment=
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<!-- Atomic properties -->
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|atomic properties comment=
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|oxidation states='''3''', 2, 1
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|oxidation states ref=
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|oxidation states comment=(a strongly basic oxide)
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|electronegativity=1.10
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|electronegativity ref=
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|electronegativity comment=
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|ionization energy 1=538.1
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|ionization energy 1 ref=
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|ionization energy 1 comment=
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|ionization energy 2=1067
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|ionization energy 2 ref=
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|ionization energy 2 comment=
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|ionization energy 3=1850.3
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|ionization energy 3 ref=
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|ionization energy 3 comment=
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|number of ionization energies=
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|ionization energy ref=
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|ionization energy comment=
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|atomic radius=187
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|atomic radius ref=
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|atomic radius comment=
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|atomic radius calculated=
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|atomic radius calculated ref=
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|atomic radius calculated comment=
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|covalent radius=207±8
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|covalent radius ref=
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|covalent radius comment=
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|Van der Waals radius=
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<!-- Miscellanea -->
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|crystal structure=
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|crystal structure prefix=
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|crystal structure ref=
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|crystal structure comment= Double hexagonal close-packed (dhcp)
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|crystal structure 2=
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|crystal structure 2 prefix=
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|crystal structure 2 comment=
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|speed of sound=
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|speed of sound ref=
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|speed of sound comment=
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|speed of sound rod at 20=2475
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|speed of sound rod at 20 ref=
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|speed of sound rod at r.t.=
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|speed of sound rod at r.t. ref=
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|speed of sound rod at r.t. comment=
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|thermal expansion=12.1
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|thermal expansion ref=
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|thermal expansion comment=(α, poly)
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|thermal expansion at 25=
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|thermal expansion at 25 ref=
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|thermal expansion at 25 comment=
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|thermal conductivity=13.4
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|thermal conductivity ref=
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|thermal conductivity 2=
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|electrical resistivity=6.15·10<sup>-7</sup>
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|electrical resistivity comment=(α, poly)
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|band gap=
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|Curie point K=
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|magnetic ordering=Paramagnetic
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|magnetic ordering comment=
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|tensile strength=
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|tensile strength ref=
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|tensile strength comment=
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|Young's modulus=36.6
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|Young's modulus ref=
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|Young's modulus comment=(α, poly)
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|Shear modulus=14.3
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|Shear modulus ref=
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|Shear modulus comment=(α, poly)
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|Bulk modulus= 27.9
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|Bulk modulus ref=
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|Bulk modulus comment=(α, poly)
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|Poisson ratio=0.28
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|Poisson ratio ref=
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|Poisson ratio comment=(α, poly)
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|Mohs hardness=2.5
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|Mohs hardness comment=
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|Mohs hardness 2=
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|Mohs hardness 2 comment=
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|Vickers hardness=360–1750
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|Vickers hardness comment=
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|Brinell hardness=350–400
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|Brinell hardness ref=
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|Brinell hardness comment=
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|CAS number=7439-91-0
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|CAS number ref=
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|CAS number comment=
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<!-- History -->
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|naming=
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|predicted by=
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|prediction date=
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|discovered by=Carl Gustaf Mosander
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|discovery date=1838
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|first isolation by=
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|discovery and first isolation by=
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<!-- Isotopes -->
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|isotopes=
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|engvar=
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}}
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'''Lanthanum''' is a rare-earth metal with chemical symbol '''La''', and an atomic weight of 57. Lanthanum is the first element in the [[lanthanide]] element series.
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Lanthanum's position in the [[periodic table]] is shown different depending on the type of table. Some models put it in group 3, others or at the end of the f block with [[lutetium]] and lawrencium instead, while other types of tables only have [[scandium]] and [[yttrium]], leaving lanthanum in the f block.
  
 
==Properties==
 
==Properties==
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*[http://www.sciencemadness.org/talk/viewthread.php?tid=38326 Lanthanum from pool cleaner]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=38326 Lanthanum from pool cleaner]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=12040 How to store Lanthanum metal]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=12040 How to store Lanthanum metal]
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*[https://www.sciencemadness.org/whisper/viewthread.php?tid=158708 Lanthanum metal cleaning]
  
 
[[Category:Elements]]
 
[[Category:Elements]]
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[[Category:Rare earth metals]]
 
[[Category:Rare earth metals]]
 
[[Category:Lanthanides]]
 
[[Category:Lanthanides]]
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[[Category:Reducing agents]]
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[[Category:Materials unstable in acidic solution]]
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[[Category:Materials that react with water]]
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[[Category:Air-sensitive materials]]
 
[[Category:F-block]]
 
[[Category:F-block]]

Latest revision as of 21:03, 16 October 2022

Lanthanum,  57La
General properties
Name, symbol Lanthanum, La
Appearance Silvery-white
Lanthanum in the periodic table
Y
↑
La
↓
Ac
Barium ← Lanthanum → Cerium
Atomic number 57
Standard atomic weight (Ar) 138.90547(7)
Group, block , d-block
Period period 6
Electron configuration [Xe] 5d1 6s2
Physical properties
Silvery-white
Phase Solid
Melting point 1193 K ​(920 °C, ​1688 °F)
Boiling point 3737 K ​(3464 °C, ​​6267 °F)
Density near r.t. 6.162 g/cm3
when liquid, at  5.94 g/cm3
Heat of fusion 6.20 kJ/mol
Heat of 400 kJ/mol
Molar heat capacity 27.11 J/(mol·K)
 pressure
Atomic properties
Oxidation states 3, 2, 1 ​(a strongly basic oxide)
Electronegativity Pauling scale: 1.10
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
Miscellanea
Crystal structure ​Double hexagonal close-packed (dhcp)
Speed of sound thin rod 2475 m/s (at 20 °C)
Thermal expansion 12.1 µm/(m·K) (α, poly)
Thermal conductivity 13.4 W/(m·K)
Electrical resistivity 6.15·10-7 Ω·m (α, poly)
Magnetic ordering Paramagnetic
Young's modulus 36.6 GPa (α, poly)
Shear modulus 14.3 GPa (α, poly)
Bulk modulus 27.9 GPa (α, poly)
Poisson ratio 0.28 (α, poly)
Mohs hardness 2.5
Vickers hardness 360–1750 MPa
Brinell hardness 350–400 MPa
CAS Registry Number 7439-91-0
History
Discovery Carl Gustaf Mosander (1838)
· references

Lanthanum is a rare-earth metal with chemical symbol La, and an atomic weight of 57. Lanthanum is the first element in the lanthanide element series.

Lanthanum's position in the periodic table is shown different depending on the type of table. Some models put it in group 3, others or at the end of the f block with lutetium and lawrencium instead, while other types of tables only have scandium and yttrium, leaving lanthanum in the f block.

Properties

Chemical

Lanthanum is one of the more reactive rare earth metals. It reacts slowly with cold water, and very quickly with hot water. It will also react with elemental halogens, chalcogens, as well as carbon, phosphorus, nitrogen, silicon, and boron.

Physical

Lanthanum is a silvery white metal that tarnishes quickly in contact with air. It is a very soft metal and can be cut with a knife.

Availability

Lanthanum is readily available from source such as Metallium and eBay.

Preparation

It is difficult to prepare lanthanum metal in an amateur setting, though a method for making rare earth metals, involving reducing the fluoride with calcium metal, is being developed by the Sciencemadness community.

Projects

  • Make Mischmetal
  • Nickel-metal hydride battery

Handling

Safety

Lanthanum metal will react with water to produce hydrogen, which is flammable. Lanthanum compounds are thought to be non-toxic, however not much research has been done on the toxicity so they should be handled with care.

Storage

Best stored under inert atmosphere.

Disposal

Best to try to recycle it.

References

Relevant Sciencemadness threads

Retrieved from "https://www.sciencemadness.org/smwiki/index.php?title=Lanthanum&oldid=14720"