Hafnium
Transition Metal
Hafnium (Hf) is a chemical element with atomic number 72, classified as a transition metal. At room temperature it is a solid. It was discovered in 1923 by Dirk Coster, George de Hevesy.
Properties
- Atomic number
- 72
- Atomic mass
- 178.49 u
- Category
- Transition Metal
- Group
- 4
- Period
- 6
- Block
- d-block
- Electron configuration
- [Xe] 4f¹⁴ 5d² 6s²
- Phase at STP
- Solid
- Density
- 13.31 g/cm³
- Melting point
- 2506 K (2232.8 °C)
- Boiling point
- 4876 K (4602.9 °C)
- Electronegativity
- 1.3
- Atomic radius
- 208 pm
- Ionization energy
- 6.825 eV
- Discovery
- 1923 · Dirk Coster, George de Hevesy
Common uses
Nuclear reactors, microprocessors, plasma cutting, superalloys
Did you know?
Excellent neutron absorber and used in nuclear submarine reactors.