How Can Mixtures Be Separated?

The parts of a mixture can be separated using their physical properties. These properties include size, shape, color, volume, density, and state.

One way to separate a mixture is simply to pick out each different type of matter. In a mixture of peas and carrots, you can easily pick out the carrots or the peas based on physical properties such as size, shape, and color.

You can also separate some mixtures by using a filter (FIL·tuhr). A filter separates things by size. Items smaller than the holes in the filter pass through it. Larger pieces are left behind.filter

Filters come in a variety of sizes. The type of filter you use depends on the size of the particles you want to separate. For example, a colander separates water from cooked pasta. The water passes through the holes, and the noodles stay behind.

How might you separate a mixture of salt and water? The salt particles dissolved in the water are very small. They would pass through most filters.

One way to separate this mixture is by evaporation (i·vap·uh·RAY·shuhn). Evaporation is the change of a liquid to a gas. When liquid water evaporates, it becomes a gas. It goes into the air. The salt is left behind. Another example of evaporation is the solids left behind as a ring after bathwater evaporates.evaporation

Cause and Effect What happens when a glass of salt water is left on the kitchen counter over night? What is an effect of using a filter on a glass of salt water? What is the result of using a filter on a mixture of sand and rocks?

What are three methods of separating mixtures? Answer the question… –With a partner –In your Learning Notebook

filter A filter separates things by size. Back to text

evaporation The change of a liquid to a gas. Back to text