noun, plural: hydrocarbons
A hydrocarbon is an organic molecule that consists of nothing else but carbon and hydrogen atoms. The carbon atoms are interconnected to each other by covalent bonding. This covalent bond between them may be single, double, or triple bond. The hydrocarbons may be classified according to the bond that occurs between the carbon atoms. In particular, a hydrocarbon in which the carbon atoms are connected purely by single bonds is referred to as saturated. A saturated hydrocarbon also means that it can no longer have an affinity for more hydrogen atoms because it is already saturated with hydrogen. They are also referred to as alkanes.
An unsaturated hydrocarbon is one in which it still has an affinity for additional hydrogen atoms. This is because an unsaturated hydrocarbon has one or more double or triple bonds between the carbon atoms. Those with double bonds are referred to as alkenes whereas those with triple bonds are called alkynes. These hydrocarbons can take additional hydrogen atoms by breaking the double or the triple bond (resulting to a single bond) between carbon atoms.
Aromatic hydrocarbons (also called arenes) are hydrocarbons that have at least one aromatic ring. Hydrocarbons that lack the aromatic ring are called alipathic hydrocarbons.