A substance that contains undissolved particles mixed throughout a liquid is called a

• A. Suspension
• B. Emulsion
• C. Solution
• D. Gel

Answer: (A)

When solid particles are mixed into a liquid but not dissolved, the mixture is a suspension. In a suspension, the particles are large enough to be visible and will eventually settle out or can be removed by filtration, so the mixture is not uniform like a true solution. This differs from a solution, where the substance dissolves completely at the molecular level and the mixture looks uniform. It also differs from an emulsion, which is a mixture of two immiscible liquids with droplets dispersed in one another, and from a gel, which is a semi-solid where a network holds liquid. So the term for undissolved particles distributed throughout a liquid is a suspension.