What is a solution?

A solution is defined as a homogeneous mixture of two or more substances, meaning that the components are uniformly distributed at the molecular level. In a solution, such as saltwater or sugar dissolved in water, the solute (salt or sugar) is dissolved evenly throughout the solvent (water), resulting in a consistent composition throughout the mixture. This uniformity allows for properties such as concentration and the behavior of the solution to be consistent across any sample taken.

In contrast to heterogeneous mixtures, where the individual components can often be distinguished and are not evenly distributed, a solution appears as a single phase. Pure substances, which only consist of one type of element or compound, and combinations of elements and compounds do not fit the definition of a solution as they lack the homogeneity that is characteristic of a true solution.