Rust is an iron oxide, a usually red oxide formed by the redox reaction of iron and oxygen in the presence of water or air moisture. Several forms of rust are distinguishable both visually and by spectroscopy, and form under different circumstances. Rust consists of hydrated iron(III) oxides Fe2O.
The rust is basic in nature when compared to other oxides. It is formed due to the occurrence of the oxygen salt of iron.
The material so formed is insoluble in water. Rust is a metal oxide created from iron; therefore it has the central atom that is more electropositive.
As a result, it is more basic than the non metal oxides such as N20.