What is the chemical formula for a phosphate group?

The chemical formula for a phosphate group is denoted as PO4^3-. This notation indicates a phosphorus atom centrally bonded to four oxygen atoms, where one of the oxygen atoms is double-bonded to the phosphorus, and the group carries a total negative charge of 3. The phosphate group is a crucial component of many biological molecules, such as nucleotides, and plays a key role in energy metabolism as seen in ATP (adenosine triphosphate).

In contrast, the other options represent different functional groups or molecular entities that do not describe a phosphate group. For example, R-SH signifies a thiol group, which contains sulfur and is not related to phosphorus. Similarly, =O NH2 describes an amide or an amine group with a carbonyl, and C-O-C signifies an ether group, none of which correspond to the structure or function of a phosphate group in biochemistry. Thus, recognizing the structure and charge of phosphate is essential for understanding its roles in biological systems.