Initially, bare Cu metal atoms react with air to form the pink oxide, cuprite, Cu2O, which has Cu+1 cations. This gradually oxidizes further to the black oxide, tenorite, CuO, with Cu+2 ions. The black sulfide CuS also sometimes forms. read more
Hi, It slightly reacts with ambient oxygen to form black-brown layer of its oxide. read more
The copper metal reacts with oxygen, resulting in the formation of an outer layer of copper oxide, which appears green or bluish-green in color. This layer is known as the patina. Unlike other destructive oxidation processes, the patina acts as a protective layer, and it does not cause any weakness in the metal. read more