Introduction to Matter (Book)

Mixtures have different properties depending on the size of their particles. Three types of mixtures based on particle size are described below. Figure below shows examples of each type. You can watch videos about the three types of mixtures at these links:

• A solution is a homogeneous mixture with tiny particles. An example is salt water. The particles of a solution are too small to reflect light. As a result, you cannot see them. That’s why salt water looks the same as pure water. The particles of solutions are also too small to settle or be filtered out of the mixture.
• A suspension is a heterogeneous mixture with large particles. An example is muddy water. The particles of a suspension are big enough to reflect light, so you can see them. They are also big enough to settle or be filtered out. Anything that you have to shake before using, such as salad dressing, is usually a suspension.
• A colloid is a homogeneous mixture with medium-sized particles. Examples include homogenized milk and gelatin. The particles of a colloid are large enough to reflect light, so you can see them. But they are too small to settle or filter out of the mixture.