Category:Refractory metals

Refractory metals are a class of transition metals that have extraordinary resistence to heat and wear. The class consists of five elements: niobium, molybdenum, tantalum, tungsten, and rhenium; though some definitions also include the fourth group metals (titanium, zirconium, hafnium), vanadium, chromium and the platinum metals from the 8th and 9th group.

A common chemical property of refractory metals is that they do not form basic oxides and hydroxides (or do so extremely reluctantly), and their low-oxidated compounds are unstable. Their most stable oxides are acidic in character.