Copper

Copper, chemical element, symbol Cu; for physical constants see Periodic Table. Copper was discovered in prehistoric times. It is a metallic element occasionally occurring in pure form. The most important ore is chalcopyrite. Copper is a reddish metal, malleable and ductile, a good conductor of heat and electricity. Brass, bronze, monel metal, and gun metal are all important alloys of copper. Most copper is used in the electrical industry. Some copper compounds are used as pesticides.