NO. 072Transition

Hf

Hafnium

Hafnium is used in nuclear reactors due to its excellent neutron absorption capability.

Crystal Structure

Hexagonal close-packed (hcp)

Atomic Mass178.49 u

Density13.31 g/cm³

Melting Point2506 K

Boiling Point4876 K

Atomic Radius159 pm

Electronegativity1.3

Ionization Energy659 kJ/mol

Electron Affinity0 kJ/mol

Bonding TypeMetallic

Oxidation States4

Acid/BaseBasic

ReactivityLow

Electron Configuration

[Xe] 4f14 5d2 6s2

Discovered ByDirk Coster

Year1923

Known Isotopes

Hf-174Hf-176Hf-177Hf-178Hf-179Hf-180