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Atomic: M.A.C. | Reference
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Thulium
Electrons per shell 2,8,18,31,8,2
Electron Configuration [Xe] 4f13 6s2 open electron config
Ground state 27/2
Atomic Volume 18.1 cm3 mol-1
Electronegativity 1.25
Magnetic ordering No data
Mass magnetic susceptibility 1.99 x 10-6
Molar magnetic susceptibility 3.36179 x 10-7
Thermal Properties
Enthalpy of Atomization 247 kJ mol-1 @25°C
Enthalpy of Fusion 18.4 kJ mol-1
Enthalpy of Vaporisation 247 kJ mol-1
Heat Capacity 27.03 J mol-1 K-1
Thermal Conductivity 16.9 W m-1 K-1
Thermal Expansion 13.3 μm m-1 K-1
Hardness
Brinell hardness 471 MPa
Vickers hardness 520 MPa
Elastic Properties
Bulk modulus 44.5 GPa
Poisson ratio 0.213
Shear modulus 30.5 GPa
Young's modulus 74.0 GPa
Electrical Properties
Electrical resistivity 7.0 x 10-7 Ω m
Electrical conductivity 0.015 106/cm Ω
Chemical Properties
Electrochemical Equivalent 2.101 g Ah-1
Valence Electron Potential (-eV) 49.7
Ionization Potential  
First 6.184
Second 12.054
Third 26.367
Energy Levels
Kα1 (intensity 100) 50.7416 KeV
Kα2 (intensity 50) 49.7726 KeV
Kβ1 (intensity 24.3) 57.517 KeV
Kβ2 (intensity 9.1) 58.7551 KeV
Kβ3 (intensity 9.7) 57.3519 KeV
Lα1 (intensity 100) 7.1799 KeV
Lα2 (intensity 10) 7.1331 KeV
Lβ1 (intensity 44.5) 8.101 KeV
Lβ2 (intensity 19.5) 8.468 KeV
Lβ3 (intensity 9) 8.232 KeV
Lβ4 (intensity 4) 8.0239 KeV
Lγ1 (intensity 7) 9.426 KeV
Lγ2 (intensity 2.4) 9.7366 KeV
Lγ3 (intensity 2) 7.307 KeV
Ll (intensity 5) 6.3389 KeV
Atomic Radii
Empirical 175 pm
Bohr Radius 222 pm
Covalent Radius No data.
Van der Waals No data.
Triple covalent No data.
Metallic 175.9 pm
Oxidation States
Main Tm+3
Other Tm+2
Ionisation Energies (kJ mol-1) show graph
M - M+ 596.7
M+ - M2+ 1163
M2+ - M3+ 2285
M3+ - M4+ 4119
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 1117 1235 1381 1570 (1821) (2217)
Crystal Structure
Structure Hexagonal close packed
a = 353.75 pm
b = 353.75 pm
c = 555.46 pm
α = 90°
β = 90°
γ = 120°