How can you tell a solution from a colloid?

A solution is a homogeneous mixture where one substance (the solute) is completely dissolved in another (the solvent). The particles in a solution are at the molecular or ionic level, making them too small to be seen. Solutions do not scatter light and have a uniform composition throughout, which means they appear clear and transparent.

Colloids are mixtures where fine particles of one substance are dispersed within another, but not dissolved. These particles are larger than those in solutions, typically ranging from 1 nanometer to 1 micrometer. Colloids can scatter light, a phenomenon known as the Tyndall effect, and they often appear cloudy or opaque, distinguishing them from clear solutions.

To differentiate between a solution and a colloid, various separation techniques can be employed. For instance, filtration can separate colloidal particles from a liquid, as they are larger than the pores of the filter. Additionally, centrifugation can be used to separate colloids based on particle size and density, while solutions remain homogeneous and cannot be separated by these methods.