Description | The phosphate ion is a polyatomic ion with the empirical formula PO4H and a molecular mass of 94.97 daltons; it consists of one central phosphorus atom surrounded by four identical oxygen atoms in a tetrahedral arrangement. It is a hypervalent molecule (the phosphorus atom has 10 electrons in its valence shell). A phosphate, in inorganic chemistry, is a salt of phosphoric acid. Phosphates are also important in biochemistry and biogeochemistry. In agriculture phosphate refers to one of the three primary plant nutrients, and it is a component of fertilizers. In ecological terms, because of its important role in biological systems, phosphate is a highly sought after resource. Consequently, it is often a limiting reagent in environments, and its availability may govern the rate of growth of organisms. Addition of high levels of phosphate to environments and to micro-environments in which it is typically rare can have significant ecological consequences. In the context of pollution, phosphates are a principal component of total dissolved solids, a major indicator of water quality. |