Solution, Suspension, and Colloid
Solutions are homogeneous mixtures where two or more substances blend completely. The particles in solutions are extremely tiny (molecules or ions), making them impossible to see with the naked eye. When you shine light through a solution, the beam passes straight through without scattering.
Suspensions are heterogeneous mixtures containing larger undissolved particles that you can often see separating over time. These particles are large enough to be visible and can be removed through filtration. Think of muddy water as a classic example - the dirt eventually settles at the bottom.
Try This! Shine a flashlight through water with a few drops of milk added. Can you see the beam? This demonstrates the Tyndall effect in colloids!
Colloids exist in an intermediate state between solutions and suspensions. Though they're heterogeneous mixtures, their particles remain evenly distributed and don't settle out over time. The unique property of colloids is the Tyndall effect - they scatter light beams passing through them, making the beam visible. Milk is a perfect example of a colloid, containing tiny fat droplets and proteins dispersed in water.