Technical data for Hafnium

Overview
NameHafnium
SymbolHf
Atomic Number72
Atomic Weight178.49
Density13.31 g/cm3
Melting Point2233 °C
Boiling Point4603 °C

Thermal properties
PhaseSolid
Melting Point2233 °C
Boiling Point4603 °C
Absolute Melting Point2506 K
Absolute Boiling Point4876 K
Heat of Fusion25.5 kJ/mol
Heat of Vaporization630 kJ/mol
Heat of CombustionN/A
Specific Heat144 J/(kg K)[note]
Thermal Conductivity23 W/(m K)
Thermal Expansion5.9×10-6 K-1

Bulk physical properties
Density13.31 g/cm3
Density (Liquid)12 g/cm3
Molar Volume0.0000134102
Brinell Hardness1.7×103 MPa
Mohs Hardness5.5 MPa
Vickers Hardness1760 MPa
Bulk Modulus110 GPa
Shear Modulus30 GPa
Young Modulus78 GPa
Poisson Ratio0.37
Speed of Sound3010 m/s
Thermal Conductivity23 W/(m K)
Thermal Expansion5.9×10-6 K-1

Reactivity
Valence4
Electronegativity1.3
ElectronAffinity0 kJ/mol
Ionization Energies
658.5, 1440, 2250, 3216 kJ/mol

Health and Safety
Autoignition PointN/A
FlashpointN/A

Classifications
Alternate NamesNone
Nams of AllotropesNone
Blockd
Group4
Period6
Electron Configuration[Xe]4f145d26s2
ColorGray
Discovery
1923 in Denmark
Gas phaseN/A
CAS NumberCAS7440-58-6

Electrical properties
Electrical TypeConductor
Electrical Conductivity3.3×106 S/m
Resistivity3×10-7 m Ω
Superconducting Point0.128

Magnetic properties
Magnetic TypeN/A
Curie PointN/A
Mass Magnetic Susceptibility5.3×10-9
Molar Magnetic Susceptibility9.46×10-10
Volume Magnetic Susceptibility0.0000705

Abundances
% in Universe7×10-8%
% in Sun1×10-7%
% in Meteorites0.000017%
% in Earth's Crust0.00033%
% in Oceans8×10-10%
% in HumansN/A

Atomic dimensions and structure
Atomic Radius208 pm
Covalent Radius150 pm
Van der Waals RadiusN/A
Crystal StructureSimple Hexagonal
Lattice Angles
π/2, π/2, 2 π/3
Lattice Constants
319.64, 319.64, 505.11 pm
Space Group NameP63/mmc
Space Group Number194

Nuclear Properties
Half-LifeStable
LifetimeStable
Stable Isotopes
176Hf, 177Hf, 178Hf, 179Hf, 180Hf
Isotopic Abundances
174Hf0.16%
176Hf5.26%
177Hf18.6%
178Hf27.28%
179Hf13.62%
180Hf35.08%

Notes on the properties of Hafnium:
Specific Heat: Value given for solid phase.