If the solute particles dissolve in the solvent, but are still visible in the homogeneous mixture (cloudy), then a colloidal dispersion has formed. A colloidal dispersion can be identified by a simple experiment called the Tyndall Effect. If a beam of light is shined through a colloidal dispersion, that beam will be visible because the light will be reflected by the colloid particles. This is called the Tyndall Effect. If a beam of light is shined through a solution, the beam will not be visible because the solute particles are too small to reflect the light. (This effect will be demonstrated in a laboratory exercise.) Try to think of some examples of colloidal dispersions. (There are several listed in your text if you need some help.)

A suspension is formed when the solute particles do not dissolve in the solvent. This is a heterogeneous mixture. The weight of the suspended particles causes them to settle out. Can you think of some examples of suspensions? Practically anything that says to "shake well before using" is an example of a suspension.