The most general classification of chemical compounds is that of inorganic and organic substances. Inorganic substances generally do not contain a carbon atom, whereas organic substances contain several. Our bodies are composed mostly of water, H 2 O, and it is necessary for us to survive. However, water is an example of an inorganic compound because it does not contain carbon and it was not formed by a living organism. Water is an inorganic compound, a solvent.