Nickel is a hard, silvery-white metal that can be combined with other metals, such as iron, copper, chromium, and zinc, to form alloys. These alloys are used to make coins, jewelry, and items such as valves and heat exchangers. Most nickel is used in the production of stainless steel. Nickel can also combine with other elements, such as chlorine, sulfur, and oxygen, to form nickel compounds. Many nickel compounds dissolve fairly easily in water and have a green color. Nickel compounds are used for nickel plating, coloring ceramics, manufacturing some batteries, and as catalysts that increase the rate of chemical reactions.

Nickel has the atomic symbol Ni, atomic number 28, and an atomic weight of 58.69.