Hafnium

Transition metal · 178.49 u · group 4, period 6

Hafnium · Hf

Atomic number72

SymbolHf

CategoryTransition metal

Standard stateSolid

Group · Period · Block4 · 6 · d

Electron configuration[Xe]6s2 4f14 5d2

Atomic mass178.49 u

Atomic radius212 pm

Protons / Neutrons / Electrons72 / 106 / 72

Shells (e⁻ per shell)2, 8, 18, 32, 10, 2

Electronegativity (Pauling)1.3

Ionization energy6.825 eV

Electron affinity—

Oxidation states+4

Melting point2.51e+3 K · 2.23e+3 °C

Boiling point4.88e+3 K · 4.60e+3 °C

Density13.3 g/cm³

Year discovered1923

CPK color

#4DC2FF

State at room temp (25 °C)

solid

Position