Which type of mixture maintains a uniform composition throughout?

A homogeneous mixture maintains a uniform composition throughout, meaning that its components are evenly distributed and cannot be easily distinguished from one another. Examples of homogeneous mixtures include solutions like saltwater or air, where the different substances blend thoroughly at the molecular level.

In contrast, a colloidal mixture has microscopic particles that remain suspended in the medium but do not settle out, leading to a typically cloudy appearance without a uniform composition. Heterogeneous mixtures consist of visibly different substances or phases that can be separated physically and do not blend uniformly; examples include salad or granite. Suspensions are mixtures where solid particles are dispersed in a liquid but will settle over time when left undisturbed, indicating a lack of uniformity.

Thus, the defining feature of a homogeneous mixture is its consistent composition, making it indistinguishable in appearance regardless of where a sample is taken from within the mixture.