Which compound is commonly known as nitrogen monoxide?

The compound commonly known as nitrogen monoxide is indeed represented by the formula NO. Nitrogen monoxide, also referred to as nitric oxide, consists of one nitrogen atom bonded to one oxygen atom. This compound is a colorless gas that plays a significant role in various biological processes and industrial applications, including its involvement as a signaling molecule in the cardiovascular system.

The structure of NO is straightforward, with one nitrogen (N) atom and one oxygen (O) atom, which is reflected in its molecular formula. Understanding the nomenclature helps with recognizing that "mono" in nitrogen monoxide indicates a single nitrogen atom is combined with a single oxygen atom.

The other compounds listed do not correspond to nitrogen monoxide. For instance, N2O5 is dinitrogen pentoxide, CO represents carbon monoxide, and SO2 is sulfur dioxide. Each of these has a distinct molecular structure and composition that differentiates them from nitrogen monoxide. Thus, recognizing the molecular formula is key in identifying the correct compound from the options provided.