Hafnium
Symbol: Hf
Atomic Number: 72
Atomic Weight: 178.49
Element Classification: Transition Metal
Electron Configuration: [Xe] 4f14 5d2 6s2
Discovery: Dirk Coster and Georg von Hevesy 1923 (Denmark)
Name Origin: Hafnia, the Latin name of Copenhagen.
Density (g/cc): 13.31
Melting Point (K): 2503
Boiling Point (K): 5470
Appearance: silvery, ductile metal
Atomic Radius (pm): 167
Atomic Volume (cc/mol): 13.6
Covalent Radius (pm): 144
Ionic Radius: 78 (+4e)
Specific Heat (@20°C J/g mol): 0.146
Fusion Heat (kJ/mol): (25.1)
Evaporation Heat (kJ/mol): 575
Pauling Negativity Number: 1.3
First Ionizing Energy (kJ/mol): 575.2
Oxidation States: 4
Lattice Structure: hexagonal
Lattice Constant (Å): 3.200
Lattice C/A Ratio: 1.582
References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952), CRC Handbook of Chemistry & Physics (18th Ed.)
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