- Atomic Radius (Å)
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).
72
Atomic Number
178.49
Atomic Mass (u)
2500.15
Melting Point (K)
4876
Boiling Point (K)
13.31
Density (solid: g/cm³, gas: g/liter)
2.2
Atomic Radius (Å)
1.75
Covalent Radius (Å)
1.3
Electronegativity
6.83
First Ionization Energy (eV)
17.18
Electron Affinity
6
Number of Shells
2, 8, 18, 32, 10, 2
Electron Shell Occupations
0.14
Specific Heat (J/g)