Answer:
True
Step-by-step explanation:
We need to understand the classes of compounds in organic chemistry. A compound ending with -ene shows that we're looking at an alkene.
Alkenes have one double bond which consists of a sigma and a pi bond. In order to understand whether 1-butene, an alkene, is unsaturated or not, we simply need to define what unsaturation is. Unsaturated is a synonym to a compound which has at least one double bond that can undergo addition reaction with, for example, hydrogen gas, chlorine or bromine.
Alkenes in the first place are hydrocarbons, as they consist of carbon and hydrogen atoms only, so we can answer the first part of the question. Secondly, all alkenes are unsaturated, as all of them have one double bond. That said, our strategy of identifying that 1-butene is an alkene and understanding what all alkenes have in common (all are unsaturated hydrocarbons) helps us realize that 1-butene is an unsaturated hydrocarbon just as any other alkene (IUPAC name ending with -ene).