Tantalum pentoxide (325 mesh, 99.9%) is the inorganic compound with the formula
Ta2O5.
It is a white solid that is insoluble in all solvents but is attacked by strong bases and hydrofluoric acid. Ta2O5 is an inert material with a high refractive index and low absorption (i.e. colorless), which makes it useful for coatings. It is also extensively used in the production of capacitors, due to its high dielectric constant.