Final answer:
A hydrocarbon with a six-membered ring of alternating single and double bonds is known as an aromatic hydrocarbon, with benzene being the classic example.
Step-by-step explanation:
The name given to a hydrocarbon that contains a six-membered ring of alternating single and double bonds is an aromatic hydrocarbon. The most common example of such a molecule is benzene, which consists of a hexagonal ring with six carbon atoms, where each carbon atom is bonded to one hydrogen atom. The alternating double bonds provide a structure known for its stability and unique chemical properties compared to other hydrocarbons.
Aromatic hydrocarbons are an important class of compounds in organic chemistry, with benzene being the simplest aromatic compound. The delocalization of electrons across the carbon atoms in the ring is what gives these compounds their aromaticity. This configuration is represented by resonance structures because more than one correct Lewis structure can be drawn for these compounds.