What is a solution in the context of chemistry?

In the context of chemistry, a solution is specifically defined as a mixture where one or more substances (known as solutes) are completely dissolved in another substance (known as the solvent). This process results in a homogeneous mixture at the molecular level, meaning that the individual particles of the solute are distributed uniformly throughout the solvent.

The defining characteristic of a solution is that it appears uniform and consistent in composition, regardless of sample size. This property distinguishes solutions from other types of mixtures, such as suspensions or colloids, where the components are not fully dissolved and can separate over time.

Other answer choices do not capture the essential nature of a solution. A solid mixture does not account for the dissolution process necessary for a solution. Describing a solution as a reversible chemical reaction misrepresents its definition since reactions involve transformations of substances rather than mere mixtures. Lastly, a method for separating mixtures does not align with the concept of a solution, as it pertains to techniques used to isolate components rather than describing a type of chemical mixture.