The chemical formula for nitrogen monoxide is NO, which pairs one nitrogen atom with one oxygen atom. It forms a colorless, toxic gas and is also known as nitric oxide.
According to the Encyclopedia Britannica, nitrogen monoxide has few industrial uses and is mainly an air pollutant from automobiles and factories. It is a relatively unstable molecule that reacts vigorously with oxygen to form NO2, or nitrogen dioxide, which is a much more stable form.
Mono, meaning one, and di, meaning two, are useful prefixes to understand in the naming of compounds. Nitrogen monoxide contains one oxygen atom, while nitrogen dioxide contains two. The same holds true with carbon monoxide and carbon dioxide, which contain one and two oxygen atoms respectively.