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Atomic: M.A.C. | Reference
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Hafnium
Electrons per shell 2,8,18,32,10,2
Electron Configuration [Xe] 4f14 5d2 6s2 open electron config
Ground state 3F2
Atomic Volume 13.6 cm3 mol-1
Electronegativity 1.3
Magnetic ordering No data
Mass magnetic susceptibility 5.3 x 10-9
Molar magnetic susceptibility 9.46 x 10-10
Speed of sound 3010 m s-1
Thermal Properties
Enthalpy of Atomization 703 kJ mol-1 @25°C
Enthalpy of Fusion 25.5 kJ mol-1
Enthalpy of Vaporisation 570.7 kJ mol-1
Heat Capacity 25.73 J mol-1 K-1
Thermal Conductivity 23.0 W m-1 K-1
Thermal Expansion 5.9 μm m-1 K-1
Hardness
Brinell hardness 1700 MPa
Mohs hardness 5.5
Vickers hardness 1760 MPa
Elastic Properties
Bulk modulus 110 GPa
Poisson ratio 0.37
Shear modulus 30 GPa
Young's modulus 78 GPa
Electrical Properties
Electrical resistivity 3.0 x 10-7 Ω m
Electrical conductivity 0.0312 106/cm Ω
Chemical Properties
Electrochemical Equivalent 1.6649 g Ah-1
Electron Work Function 3.9 eV
Valence Electron Potential (-eV) 81
Ionization Potential  
First 6.65
Second 14.925
Third 23.32
Incompatibilities Strong oxidizers, chlorine.
Flammability
Explosive in powder form
Energy Levels
Kα1 (intensity 100) 55.7902 KeV
Kα2 (intensity 50) 54.6114 KeV
Kβ1 (intensity 25.1) 63.234 KeV
Kβ2 (intensity 9.7) 64.3746 KeV
Kβ3 (intensity 9.9) 63.109 KeV
Lα1 (intensity 100) 7.899 KeV
Lα2 (intensity 10) 7.8446 KeV
Lβ1 (intensity 44) 9.0227 KeV
Lβ2 (intensity 19) 9.3473 KeV
Lβ3 (intensity 8) 9.1599 KeV
Lβ4 (intensity 4) 8.9039 KeV
Lγ1 (intensity 7.5) 10.5158 KeV
Lγ2 (intensity 4) 10.8324 KeV
Lγ3 (intensity 2) 8.137 KeV
Ll (intensity 5.5) 6.9583 KeV
Atomic Radii
Empirical 155 pm
Bohr Radius 208 pm
Covalent Radius 150 pm
Van der Waals No data.
Triple covalent 122 pm
Metallic 159 pm
Oxidation States
Main Hf+4
Other Hf+1, Hf+2, Hf+3
Ionisation Energies (kJ mol-1) show graph
M - M+ 642
M+ - M2+ 1440
M2+ - M3+ 2250
M3+ - M4+ 3216
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 2689 2954 3277 3679 4194 4876
Crystal Structure
Structure Hexagonal close packed
a = 319.64 pm
b = 319.64 pm
c = 505.11 pm
α = 90°
β = 90°
γ = 120°