Final answer:
An aromatic hydrocarbon is a compound with a six-membered carbon ring that has alternating single and double bonds, such as benzene.
Step-by-step explanation:
The hydrocarbon that contains a six-membered ring with alternating single and double bonds is known as an aromatic hydrocarbon. The most classic example of an aromatic hydrocarbon is benzene, which has the formula C6H6. In benzene, the six carbons create a hexagon pattern, and each carbon atom has one hydrogen attached. The unique aspect of benzene and similar aromatic hydrocarbons is their alternating single and double bonds around the ring, creating a stable structure due to delocalized electrons.
Aromatic hydrocarbons are a distinct category of unsaturated hydrocarbons that not only include benzene but also derivatives where various atoms or groups replace one or more of benzene's hydrogen atoms. These compounds exhibit significant chemical stability and special properties due to their electronic structure.