Which prefix is used to denote a compound that contains chlorine substituents?

The prefix that is used to denote the presence of chlorine substituents in an organic compound is "chloro-." This prefix is derived from the name of the element chlorine, and it is used in the naming of organic compounds to indicate that chlorine atoms are attached to the carbon chain.

For example, in a compound like chloroethane, the "chloro-" prefix signifies that one or more chlorine atoms are substituents on the ethane molecule (which consists of two carbon atoms). This systematic naming convention helps chemists quickly identify the presence and number of specific substituents in a molecular structure.

The other prefixes mentioned are associated with different halogen substituents: "fluoro-" is used for fluorine, "bromo-" for bromine, and "iodo-" for iodine. Each of these prefixes serves a similar purpose but indicates a different halogen. Hence, knowing the correct prefix and its corresponding halogen is crucial for accurately naming organic compounds.