What is the chemical formula for iron?

Iron has the chemical formula Fe from its Latin name, ferrum. Its atomic number is 26, and its molar mass is 55.845 grams per mole. It has a metallic gray color and is attracted to magnets. Iron is the second most-abundant metal on Earth.

Iron is a reactive element and reacts with most acids. Chemical compounds of iron in oxidation state +2 are called ferrous compounds, and are reducing agents. Ferric compounds contain iron in oxidation state +3, and are oxidizing agents. Pure iron corrodes in damp air to form rust. However, carbon-containing alloys, such as stainless steel, do not rust in normal conditions.