Which term describes solid particles in a liquid?

• A. Suspension
• B. Colloid
• C. Solution
• D. Alloy

Answer: (A)

In a suspension, solid particles are dispersed in a liquid but are large enough to be seen and they won’t stay mixed forever. They don’t dissolve, so the mixture looks cloudy and the solid particles will settle to the bottom if you leave it undisturbed. You can often separate the solid by letting it settle or by filtering the liquid. Muddy water or sand in water are classic examples.

In contrast, a solution has dissolved particles at the molecular level, so you can’t see any solid particles and the mixture is uniform throughout. A colloid has particles smaller than those in a suspension and these particles stay dispersed for a long time without settling quickly, though the mixture may still look cloudy. An alloy is a solid blend of metals or elements, not a liquid with solids suspended in it.