Answer:Colloids form when tiny particles (1–1000 nm) are evenly dispersed in another substance. These particles are small enough to stay suspended and not settle over time. They stay stable due to electric charges or movement.Example: Milk (fat in water), fog (water in air)Suspensions form when larger particles (>1000 nm) are mixed into a fluid. These particles are too heavy to stay mixed and will settle out over time unless stirred.Example: Muddy water, sand in water