72Solid
Hf 178.49 Atomic mass · uTransition metals
Hafnium
Hafnium is a chemical element with symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, making it the penultimate stable element to be discovered (rhenium was identified two years later).
Discovery 1923 (Dirk Coster)
K2L8M18N32O10P2
Physical properties
Values for the element in its standard state.
- Density
- 13.31g/cm³
- Melting point
- 2,506K
- Boiling point
- 4,876K
- Atomic radius
- 150pm
- Bonding type
- Metallic
- Molar heat
- 25.73J/(mol·K)
Inside the atom
Electron arrangement and the energy behind its behavior.
Full electron configuration
1s, 2 electrons; 2s, 2 electrons; 2p, 6 electrons; 3s, 2 electrons; 3p, 6 electrons; 3d, 10 electrons; 4s, 2 electrons; 4p, 6 electrons; 4d, 10 electrons; 5s, 2 electrons; 5p, 6 electrons; 4f, 14 electrons; 5d, 2 electrons; 6s, 2 electrons;
[Xe] represents 54 core electrons. The full view shows them explicitly.
72 electrons Orbital order preserved from source
- Electronegativity
- 1.3Pauling scale
- First ionization energy
- 659kJ/mol
- Electron affinity
- 0kJ/mol
- Van der Waals radius
- Not available
Hf HafniumAtomic number 72
659kJ/mol
Atomic numberGaps indicate unavailable data
About hafnium
- Appearance
- Steel gray
- Discovery
- 1923 (Dirk Coster)
- Data source
- Read the reference
A missing value means it is unavailable in this reference dataset. Values can vary with measurement method and conditions.