Periodic Table of Elements

72

Hafnium

178.49

Hafnium was discovered by Dirk Coster, a Danish chemist, and Charles de Hevesy, a Hungarian chemist, in 1923 using x-ray spectroscopy to analyze zirconium ores.

Name: Hafnium
Symbol: Hf
Atomic number: 72
Atomic weight: 178.49
State: solid
Group, period, block: 4, 6, d
Color: steel gray
Classification: transition metal
Electron configuration: 4f14 5d2 6s2
2,8,18,32,10,2

Physical properties

Density: 13.31 g/cm-3
Melting point: 2506 K, 2233 C, 4051 F
Boiling point: 4876 K, 4603 C, 8317 F

Atomic properties

Oxidation states: 4, 3, 2
Electronegativity: 1.3 (Pauling scale)
Ionization energies: 1st: 658.5 kJmol-1
Covalent radius: 17510 pm
Van der Waals radius: no data
  • Hf
  • Electron Configuration

Isotopes

There are six naturally occurring isotopes of hafnium exist, 174Hf, 176Hf, 177Hf, 178Hf, 179Hf, and 180Hf.
174Hf is radioactive isotope.