An aromatic hydrocarbon is a type of organic compound that contains one or more benzene rings, which are characterized by their distinct smell. Naphthalene is an example of an aromatic hydrocarbon, with 11 letters in its name. It is a white crystalline solid composed of two fused benzene rings and is commonly found in coal tar and crude oil. Naphthalene is used in the production of plastics, dyes, and insecticides.