All the photos show mixtures!

Mixtures in which you can see all the separate parts easily are called heterogeneous mixtures. Trail mix, soup, and iced juice are heterogeneous mixtures.

Mixtures that appear as one substance where you cannot see the various parts are called homogeneous mixtures. Salt water and steel are homogeneous mixtures. When a solute dissolves into a solvent, it produces a type of homogeneous mixture called a solution. It can be difficult to tell the difference between a homogeneous mixture and a pure substance just by looking at them.

But, shine a light on a mixture or solution, and you may be able to tell the difference. Light will scatter when it passes through heterogenous mixtures, but it will pass through homogeneous mixtures so the solution will look clear (not necessarily colourless). For example, orange juice, a heterogeneous mixture looks cloudy, but apple juice, a homogeneous mixture looks clear.

Turn on a flashlight in a dark room and observe that air is a heterogeneous mixture because it contains dust particles. The air in a breathing apparatus is a homogeneous solution of oxygen, nitrogen, carbon dioxide, and other gases.

In this activity, you will be making some of your own mixtures and identifying them as homogeneous or heterogeneous.