Copper is a relatively soft metal known as a malleable and ductile metal with high thermal and electrical conductivity. On the Mohs hardness scale, which measures the ability of a harder material to scratch a softer material, copper has a rating of 2.5 to 3.
In many countries, including the United States, copper is often alloyed with other metals to create coins. For example, most circulating U.S. coins are made from cupro-nickel, which is primarily copper with a smaller percentage of nickel. The U.S. penny, on the other hand, is currently made from copper-plated zinc.
