Halobenzene

Part of speech: noun

Definitions

1. A chemical compound made of a benzene ring in which one hydrogen atom has been replaced by a halogen such as chlorine, bromine or fluorine
2. An aromatic organic molecule consisting of a six-carbon benzene ring with a single halogen atom attached to it in place of hydrogen
3. Any of a family of aromatic hydrocarbon derivatives whose benzene ring carries one halogen substituent, used widely in chemical synthesis

Etymology: Halobenzene is a compound built from two parts. The "benzene" part traces back to the hydrocarbon first isolated by Michael Faraday in 1825, who named it after gum benzoin, the resin from which he obtained it. The "halo-" prefix comes from Greek "hals," meaning salt, and in chemistry it marks an element from the halogen group: fluorine, chlorine, bromine or iodine. Halobenzene therefore names the family of benzene molecules in which one hydrogen atom has been replaced by a halogen atom. Because the name is a plain combination of an existing prefix and an existing root, it was formed by systematic chemical naming rather than coined as a memorable word. The halogens themselves got their name in the early nineteenth century from the idea that they form salts with metals, which is why "halo-" carries the sense of salt-forming in so many chemical terms.