Molybdenum

At high temperatures (approximately 700°C) in air, molybdenum forms a volatile oxide (MoO3). It does not perform well in the presence of oxidizing agents at temperatures greater than 500°C, and requires protective coatings in order to be used practically in such environments. Molybdenum does, however, have a good resistance to hydrofluoric, hydrochloric and sulfuric acids without the presence of oxidizing agents. It has a good resistance to corrosion in low to moderate concentrations of sulfuric acid at low to moderate temperatures. Molybdenum is susceptible to oxidizers (e.g. nitric acid), and are generally resistant to alkaline solutions, although not in the presence of oxygen or oxidizing agents.