Molybdate refers to a chemical compound that contains the molybdate ion, MoO4^2-. This ion consists of one molybdenum atom surrounded by four oxygen atoms, and it is commonly found in various salts, such as sodium molybdate and ammonium molybdate. Molybdate compounds are often used in industrial applications, including catalysts and fertilizers. In addition to its industrial uses, molybdate plays a role in biological systems. It is an essential trace element for some organisms, including certain bacteria and plants, where it is involved in important enzymatic processes. Molybdenum, the element from which molybdate derives, is crucial for nitrogen fixation in legumes.