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Atomic: M.A.C. | Reference
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Terbium
Electrons per shell 2,8,18,27,8,2
Electron Configuration [Xe] 4f9 6s2 open electron config
Ground state 615/2
Atomic Volume 19.2 cm3 mol-1
Electronegativity 1.1
Magnetic ordering Ferromagnetic
Mass magnetic susceptibility 0.0000136
Molar magnetic susceptibility 2.161385 x 10-6
Speed of sound 2620 m s-1
Thermal Properties
Enthalpy of Atomization 314 kJ mol-1 @25°C
Enthalpy of Fusion 16.3 kJ mol-1
Enthalpy of Vaporisation 391 kJ mol-1
Heat Capacity 28.91 J mol-1 K-1
Thermal Conductivity 11.1 W m-1 K-1
Thermal Expansion 10.3 μm m-1 K-1
Hardness
Brinell hardness 677 MPa
Vickers hardness 863 MPa
Elastic Properties
Bulk modulus 38.7 GPa
Poisson ratio 0.261
Shear modulus 22.1 GPa
Young's modulus 55.7 GPa
Electrical Properties
Electrical resistivity 1.20 x 10-6 Ω m
Electrical conductivity 0.00889 106/cm Ω
Chemical Properties
Electrochemical Equivalent 1.9765 g Ah-1
Electron Work Function 3 eV
Valence Electron Potential (-eV) 46.8
Ionization Potential  
First 5.86
Second 11.525
Third 21.91
Energy Levels
Kα1 (intensity 100) 44.4816 KeV
Kα2 (intensity 50) 43.7441 KeV
Kβ1 (intensity 23.2) 50.382 KeV
Kβ2 (intensity 8.3) 51.6074 KeV
Kβ3 (intensity 9.4) 50.2341 KeV
Lα1 (intensity 100) 6.2728 KeV
Lα2 (intensity 10) 6.238 KeV
Lβ1 (intensity 45) 6.978 KeV
Lβ2 (intensity 17) 7.3667 KeV
Lβ3 (intensity 10) 7.0965 KeV
Lβ4 (intensity 4) 6.941 KeV
Lγ1 (intensity 6) 8.102 KeV
Lγ2 (intensity 2) 8.3908 KeV
Lγ3 (intensity 2) 6.282 KeV
Ll (intensity 4.5) 5.5521 KeV
Atomic Radii
Empirical 175 pm
Bohr Radius 225 pm
Covalent Radius No data.
Van der Waals No data.
Triple covalent No data.
Metallic 177.3 pm
Oxidation States
Main Tb+3
Other Tb+4
Ionisation Energies (kJ mol-1) show graph
M - M+ 564.6
M+ - M2+ 1112
M2+ - M3+ 2114
M3+ - M4+ 3839
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 1789 1979 (2201) (2505) (2913) (3491)
Crystal Structure
Structure Hexagonal close packed
a = 360.1 pm
b = 360.1 pm
c = 569.36 pm
α = 90°
β = 90°
γ = 120°