Which type of mixture remains uniformly mixed without requiring agitation?

• A. Suspensions
• B. Emulsions
• C. Fumigants
• D. Solutions

Answer: (D)

A solution stays uniformly mixed because the substance (solute) dissolves completely in the solvent at the molecular level. Once dissolved, its particles are too small to settle out or separate, so the mixture remains evenly distributed without any stirring. In pesticide use, a true solution provides a consistent concentration in the spray mix just by standing.

Suspensions are made of solid particles dispersed in a liquid, but those particles are large enough to settle to the bottom over time. They require shaking or stirring to re-disperse and stay uniform. Emulsions are liquids that don’t mix well (like oil and water) and need stabilizers; they can separate if left alone, so they aren’t inherently uniform without agitation. Fumigants describe gases or highly volatile forms used to penetrate spaces, not a type of mixture that stays evenly distributed on its own.

So, the type that remains uniformly mixed without agitation is a solution.