Which of the following best describes a halocarbon?

A halocarbon is defined as a halogenated hydrocarbon, which specifically means that it is a hydrocarbon that has one or more halogen atoms (like chlorine, fluorine, bromine, or iodine) substituted for hydrogen atoms. This substitution changes the properties and behavior of the hydrocarbon, leading to various applications in refrigeration, solvents, and industrial processes.

Halocarbons are significant in environmental discussions, especially concerning their effects on ozone depletion and greenhouse gas emissions. The presence of halogen atoms is what distinguishes halocarbons from simple hydrocarbons, which consist only of carbon and hydrogen atoms without any halogen substitutions.

The other options present definitions or concepts that do not fully encapsulate what a halocarbon is. A hydrocarbon that contains only carbon and hydrogen, for example, does not include halogens, thus not fitting the definition of a halocarbon. Other options similarly miss the specific characteristic of halogenation that defines halocarbons.