What property do colloids have regarding particle size?

Colloids are characterized by having particles that are intermediate in size between those found in true solutions and suspensions. In a colloid, the particles typically range from 1 nanometer to 1 micrometer in diameter, which allows them to remain dispersed throughout the medium without settling out, unlike larger particles in suspensions that may settle due to gravity. This intermediate size is key to the defining properties of colloids, as it allows them to scatter light (Tyndall effect) without being large enough to be easily visible or to settle out over time.

The unique property of particle size in colloids plays a significant role in their behavior and applications in various fields, such as food science, medicine, and material science. Understanding that colloidal particles are not visible to the naked eye, nor are they uniform and microscopic like those in some solutions, helps to clarify the distinction between different types of mixtures in physical science.