What type of mixture contains substances that are relatively large and tends to settle to the bottom unless continuously shaken?

A mixture that contains relatively large particles which can settle to the bottom unless continuously shaken is classified as a suspension. In a suspension, the solid particles are dispersed within a liquid but are not dissolved; over time, these larger particles will gravitate to the bottom due to gravity if the mixture is left undisturbed. This characteristic distinguishes suspensions from other types of mixtures.

In contrast, a solution contains solutes that are completely dissolved in a solvent, resulting in a homogeneous mixture where the individual particles are too small to settle out or be seen. A colloid also consists of particles that are larger than those found in a solution but smaller than those in a suspension, remaining suspended and not settling out, even over long periods. A general mixture can refer to any combination of substances, including solutions, suspensions, or colloids, but does not specify the properties that characterize each type. Therefore, the defining characteristics of a suspension make it the correct answer to the question asked.