Element Copper (Cu), Group 11, Atomic Number 29, d-block, Mass 63.546. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and images. Jump to main content . Periodic Table. ... Even in the United States' 5 cent piece, the nickel looks shiny and silvery, but actually contains 75% copper and only 25% nickel. ...Web