Zinc is a bluish-white metal used in countless everyday objects, though you probably don't notice it. Galvanized steel, which protects bridges, roofs, and playground equipment from rust, gets its rust-resistance from a coating of zinc. The “copper” pennies in your pocket are actually mostly zinc with a thin copper shell. Zinc also plays a crucial role inside your body: it helps your immune system fight off infections and helps cuts and scrapes heal properly.

Scientists use the chemical symbol Zn for zinc. It's classified as a metal, but not one of the strong, structural metals like iron. Instead, zinc usually works behind the scenes, protecting other metals or mixing with copper to create brass, the golden-colored alloy used in musical instruments like trumpets and saxophones.

Ancient metalworkers in India and China knew how to extract zinc from ore, and Roman craftsmen used brass (even if they didn't realize zinc was the secret ingredient that transformed copper into that golden alloy).