The element with the symbol "Cu" is copper. Copper is a reddish-brown metal known for its excellent electrical and thermal conductivity. It is widely used in electrical wiring, plumbing, and the manufacturing of various alloys, including brass and bronze. Copper also has antimicrobial properties, making it beneficial for use in surfaces and tools that require sanitation. It plays an essential role in biological systems, being a necessary trace element for human health. Copper is abundant in the Earth's crust and can be found in minerals such as chalcopyrite and malachite.