Hf
Hafnium
Atomic number: 72Mass: 178.49 uCategory: Transition Metal
About Hafnium
Hafnium is a lustrous, silvery grey, tetravalent transition metal. It closely resembles zirconium and is very resistant to corrosion. Hafnium is a member of the refractory metals, which are exceptionally resistant to heat and wear.
Properties
Period
6
Group
4
Block
D
Category
Transition Metal
Electronegativity
1.30 (Pauling)
Ionization Energy
658.5 kJ/mol
Melting Point
2506 K (2233°C)
Boiling Point
4876 K (4603°C)
Density
13.31 g/cm³
Oxidation States
+4
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d² 6s²
[Xe] 4f¹⁴ 5d² 6s²
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:18e⁻
Shell 4:32e⁻
Shell 5:10e⁻
Shell 6:2e⁻
Real-World Uses
Nuclear reactor control rods
Microprocessor gate dielectrics
High-temperature alloys
Plasma cutting
Spacecraft
Fun Fact
Hafnium was one of the last stable elements to be discovered — found in 1923, it had been hiding inside zirconium samples for decades!