What term describes compounds that have a carbon-hydrogen framework with one or more hydrogen atoms replaced by other elements?

• A. Hydrocarbons
• B. Hydrocarbon derivatives
• C. Alkanes
• D. Alkenes

Answer: (B)

The idea being tested is substitution on a carbon-hydrogen framework. When one or more hydrogen atoms are replaced by other elements, the resulting compounds are called hydrocarbon derivatives. This term captures all substituted members—halogenated, hydroxylated, or otherwise functionalized hydrocarbons—where the carbon skeleton remains, but additional elements sit in place of hydrogen.

Other options describe different groups: hydrocarbons are strictly C and H; alkanes and alkenes are specific types of hydrocarbons (saturated and unsaturated) that still only contain carbon and hydrogen. For example, chloromethane has chlorine in place of a hydrogen, so it’s a hydrocarbon derivative, not a hydrocarbon itself.