Hafnium - ASCII Periodic Table of the Elements

ASCII PERIODIC TABLE OF THE ELEMENTS

  Hf

Relative atomic mass: 178.49 +- 0.02

English: Hafnium
French: Hafnium
Croatian: Hafnij
German: Hafnium
Italian: Afnio
Spanish: Hafnio

Atomic number: 72
Group numbers: 4
Period: 6
Standard state (20 ^oC): solid

Discovery: 1923 Dirk Coster (NL), George Charles von Hevesy (HU)

Hafnium was discovered by Dirk Coster (NL) and George Charles von Hevesy (HU) in 1923. The origin of the name comes from the Latin name 'Hafnia' meaning 'Copenhagen'. It is a silvery, ductile, toxic metal that resists alkalis and acids (except HF). Metal ignites and burns readily and the exposed surfaces form oxide film. Hafnium is obtained from mineral zircon or baddeleyite. It is used in reactor control rods because of its ability to absorb neutrons.

Electronic configuration: [Xe] 4f¹⁴ 5d² 6s²
Formal oxidation number: +4
Atomic radius: 156.4 pm

Electronegativities: 1.3
Thermal conductivity: 23 W/(m K)
Electrical resistivity (20 ^oC): 33.08 microOhm cm

Melting point: 2233 ^oC
Boiling point: 4603 ^oC

Heat of fusion: 25.5 kJ/mol
Heat of vaporization: 570.7 kJ/mol
Heat of atomization: 618.9 kJ/mol