Chemical properties:

Niobium is stable in the air at room temperature, and is not completely oxidized when it is red hot in oxygen. It is directly combined with sulfur, nitrogen and carbon at high temperature, and can form alloys with titanium, zirconium, hafnium and tungsten. Does not interact with inorganic acids or bases, nor is it soluble in aqua regia, but soluble in hydroacids. Niobium metal is extremely stable in air at room temperature and does not interact with air. Although it has a higher melting point (2468°C) in its elemental state, its density is lower than that of other refractory metals. Niobium is also resistant to various types of erosion and can form a dielectric oxide layer.