Gasoline is a mixture. It is not an element or a compound. Gasoline is made up of various hydrocarbons, which are compounds themselves, but gasoline as a whole is a blend of these different compounds. This means it does not have a fixed composition and can vary in its chemical makeup.
Hydrocarbons are organic compounds consisting entirely of hydrogen and carbon. In gasoline, these hydrocarbons include substances like octane, heptane, and others. The exact composition of gasoline can vary depending on its source and the refining process it undergoes. This variability is a key characteristic of mixtures, as opposed to elements or compounds, which have fixed compositions.
In summary, gasoline is a mixture because it is composed of multiple different hydrocarbons blended together, and its composition is not fixed.