Hafnium
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Description
A shiny, ductile metallic element first identified in 1923. Hafnium has an abundance in the earth's crust of about 5 ppm. It is found in the minerals Zircon, cyrtolite, alvite, and malacon. Hafnium occurs naturally with Zirconium and the two metals are very difficult to separate. It is used as a neutron absorbing material in nuclear reactors, as a filament in lightbulbs and as a cathode in x-ray tubes. Hafnium is also used as an oxygen and nitrogen scavenger.
Synonyms and Related Terms
Hf; afnio (It.); Háfnio (Port.); hafnio (Esp.)
Risks
- Toxic by inhalation.
- Powder is explosive in air.
- Sigma-Aldrich: SDS (powder)
Physical and Chemical Properties
Soluble in warm HCl and sulfuric acid. Resistant to weak acids and their salts.
| Composition | Hf (atomic no. 72) |
|---|---|
| CAS | 7440-58-6 |
| Mohs Hardness | 5.5 |
| Melting Point | 2227-2233 C |
| Density | 13.3 g/ml |
| Molecular Weight | atomic wt = 178.49 |
| Boiling Point | 4602-4603 C |
Resources and Citations
- Web Elements: Website
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998