Carbon of interconnecting carbon–carbon bonds, a property that is called catenation. Carbon-carbon bonds are strong and stable. Through catenation, carbon forms a countless number of compounds. A tally of unique compounds shows that more contain carbon that those that do not. A similar claim can be made for hydrogen because most organic compounds also contain hydrogen. The simplest form of an organic molecule is the hydrocarbon—a large family of organic molecules that are composed of hydrogen atoms bonded to a chain of carbon atoms. A hydrocarbon backbone can be substituted by other atoms, known as heteroatoms. Common heteroatoms that appear in
Asymmetric carbon for all then-known phenomena of molecular asymmetry (which involved a carbon atom bearing four different atoms or groups). Knowing the number of asymmetric carbon atoms, one can calculate the maximum possible number of stereoisomers for any given molecule as follows: As an example, malic acid has 4 carbon atoms but just one of them is asymmetric. The asymmetric carbon atom is the one attached to two carbon atoms, an oxygen atom, and a hydrogen atom. One may initially be inclined to think this atom is not asymmetric because it is attached to two carbon atoms, but because those two carbon