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Atomic: M.A.C. | Reference
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Lanthanum
Electrons per shell 2,8,18,18,9,2
Electron Configuration [Xe] 5d1 6s2 open electron config
Ground state 2D3/2
Atomic Volume 20.73 cm3 mol-1
Electronegativity 1.1
Magnetic ordering No data
Mass magnetic susceptibility 1.1 x 10-8
Molar magnetic susceptibility 1.528 x 10-9
Speed of sound 2475 m s-1
Thermal Properties
Enthalpy of Atomization 431 kJ mol-1 @25°C
Enthalpy of Fusion 10.04 kJ mol-1
Enthalpy of Vaporisation 402.1 kJ mol-1
Heat Capacity 27.11 J mol-1 K-1
Thermal Conductivity 13.4 W m-1 K-1
Thermal Expansion 12.1 μm m-1 K-1
Hardness
Brinell hardness 363 MPa
Mohs hardness 2.5
Vickers hardness 491 MPa
Elastic Properties
Bulk modulus 27.9 GPa
Poisson ratio 0.280
Shear modulus 14.3 GPa
Young's modulus 36.6 GPa
Electrical Properties
Electrical resistivity 6.1 x 10-7 Ω m
Electrical conductivity 0.0126 106/cm Ω
Chemical Properties
Electrochemical Equivalent 1.7275 g Ah-1
Electron Work Function 3.5 eV
Valence Electron Potential (-eV) 40.71
Ionization Potential  
First 5.58
Second 11.059
Third 19.174
Energy Levels
Kα1 (intensity 100) 33.4418 KeV
Kα2 (intensity 50) 33.0341 KeV
Kβ1 (intensity 21.1) 37.801 KeV
Kβ2 (intensity 6.7) 38.7215 KeV
Kβ3 (intensity 8.9) 37.7144 KeV
Lα1 (intensity 100) 4.65097 KeV
Lα2 (intensity 10) 4.63423 KeV
Lβ1 (intensity 49) 5.0421 KeV
Lβ2 (intensity 18.5) 5.3835 KeV
Lβ3 (intensity 9) 5.1436 KeV
Lβ4 (intensity 4) 5.0623 KeV
Lγ1 (intensity 6.2) 5.7885 KeV
Lγ2 (intensity 2.6) 6.0595 KeV
Lγ3 (intensity 2) 4.523 KeV
Ll (intensity 4.5) 4.123 KeV
Atomic Radii
Empirical 195 pm
Bohr Radius No data.
Covalent Radius 169 pm
Van der Waals No data.
Triple covalent 139 pm
Metallic 187 pm
Oxidation States
Main La+3
Other
Ionisation Energies (kJ mol-1) show graph
M - M+ 538.1
M+ - M2+ 1067
M2+ - M3+ 1850
M3+ - M4+ 4819
M4+ - M5+ 6400
M5+ - M6+ 7600
M6+ - M7+ 9600
M7+ - M8+ 11000
M8+ - M9+ 12400
M9+ - M10+ 15900
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 2005 2208 2458 2772 3178 3726
Crystal Structure
Structure Hexagonal close packed
a = 377.2 pm
b = 377.2 pm
c = 1214.4 pm
α = 90°
β = 90°
γ = 120°