Why is carbon monoxide not an element?

Answer 1

Carbon monoxide is not an element because each molecule, the smallest unit of the substance that can exist, is a chemical combination of an atom of carbon and an atom of oxygen. A link to the Wikipedia article on this substance is provided.

Answer 2

There is not an atom called a graphite atom. Graphite, a natural mineral, is a form (allotrope) of the element carbon, and it is composed of carbon atoms. But graphite is not the only allotrope of carbon. There are also diamonds and amorphous carbon.

Answer 3

Chemists like to use informative names for chemicals. Since there are two common oxides of carbon, which are carbon monoxide (CO) and carbon dioxide (CO2) it would be less informative if we just called both of them carbon oxide. The distinction is often quite important, because carbon monoxide is quite toxic, while carbon dioxide is not toxic, and is a normal component of the atmosphere (although at the present time, we do have a bit too much of it).

Answer 4

An element consists of only 1 atom.

Carbon Monoxide, CO, has 2 atoms: 1 carbon and 1 oxygen. Hence making carbon monoxide a compound not an element.