Chemical symbol Cu. Element No. 29 of the periodic system, atomic weight 63.57. A characteristically reddish metal of bright luster, highly malleable and ductile and having high electrical and heat conductivity; melting point 1981 (degrees) F.; boiling point 4327 F.; specific gravity 8.94. Used in the pure state or alloyed by other elements to make brasses and bronzes consumed in building construction, electric and electronic products, industrial machinery, transportation equipment, and numerous consumer and general products. Used in the pure state as sheet, tube, rod and wire and also as alloyed by other elements and an alloy with other metals.