Section 2: Types of Mixtures
A solution is the most common type of a homogeneous mixture comprised of particles that are so small that they cannot even be seen with a microscope. A solution must have one or more substances dissolved into another substance. A solution will also never settle to the bottom of its container. Vinegar and hydrogen peroxide are examples of solutions.
A colloid is a type of mixture with particles that are larger than those in the solution but still too light to settle out. Fog is an example of a colloid. Fog has tiny drops of water spread throughout the air. Detecting colloids can be difficult, but shining a beam of light at a colloid will make the light scatter. This scattering of light is called the Tyndall effect. A suspension is a heterogeneous mixture containing a liquid in which visible particles settle. Italian dressing and chocolate milk are suspensions.