Final answer:
Colloids are groups of soil particles held together by colloidal particles, which are smaller than those found in suspensions. Examples include fog, milk, and butter.
Step-by-step explanation:
Colloids are groups of soil particles that are held together by colloidal particles. Colloidal particles, which are typically smaller than those found in suspensions, range in size from 2 to about 500 nanometers in diameter. Examples of colloids include fog (liquid particles in a gas), milk (solid particles in a liquid), and butter (solid particles in a solid).