Salt water: Salt water is a solution. It is a mixture of water (the solvent) and salt (the solute). The salt dissolves in the water and forms a uniform mixture.
Gasoline: Gasoline is not a solution. It is a mixture of different hydrocarbons and other chemicals, but it does not form a homogeneous mixture.
Carbon: Carbon is not a solution. It is a solid element that can exist in different forms, including graphite, diamond, and carbon black.
