Sn, or tin, is a chemical element with the symbol Sn and atomic number 50. It is a silvery-white metal known for its malleability and resistance to corrosion. Tin is commonly used in alloys, such as bronze, and as a coating for other metals to prevent rusting. Tin has been used by humans for thousands of years, dating back to ancient civilizations. It is often found in nature as part of the mineral cassiterite, which is the primary source of tin. Today, tin is also used in soldering, plating, and various industrial applications.