The chemical element copper has the atomic number 29 and the symbol Cu, which comes from the Latin cuprum. It is an extremely high thermal and electrical conductivity metal that is ductile, soft, and malleable. Pure copper has a pinkish-orange tint when it is first exposed. In addition to being used as a building material and heat and electricity conductor, copper is also a component of many metal alloys, including sterling silver, which is used in jewelry, cupronickel, which is used to make coins and marine hardware, and constantan, which is used in strain gauges and thermocouples to measure temperature.