Name hafnium
Symbol Hf
Atomic Weight 178.49
Atomic Number 72
CAS ID 7440-58-6
Group Number 4
Group Name (none)
Period Number 6
Origin of Name Latin, Hafnia = "Copenhagen."
Year Discovered 1923
Discovery Credits Discovered by D. Coster and G. C. von Hevesey at Copenhagen, Denmark.
Class Metallic
Color Grey Silvery
Standard State Solid at 77 F & 298 K
Description Lustrous, silvery, ductile metal. Resists corrosion due to oxide film, but powdered Hf will burn in air. Unaffected by acids (except HF) and alkalis. Used in control rods for nuclear reactors; high temperature alloys and ceramics.

Diagnostic tests: 
there are no simple chemical tests for hafnium.  Zirconium minerals commonly contain hafnium. Energy Dispersive Analysis of X-rays (EDAX) is used for qualitative and quantitative analysis.

Back to Elements Table Page