Solutions and Other Mixtures-02

When some chemical elements are mixed, they make compounds. For example, when hydrogen gas and oxygen gas combine, they form new chemical bonds. This creates an entirely new substance: water (H20). Even though water is made of two different elements, it is a pure substance. A glass of water contains only water molecules.

Not all matter will chemically combine when mixed. Some gases, like nitrogen, oxygen, and carbon dioxide, will not form new bonds when placed together. Instead these gases make a mixture called air.

Air is not a compound because the groups of atoms are not joined together. Instead, they are just mixed together. Many common substances, such as wet sand, are mixtures. Wet sand is a mixture made of sand and water. The trail mix in your lunch bag is also a mixture. In a mixture, properties of the individual substances are not changed.


Some mixtures are heterogeneous, which means that the components of the mixture do not look uniform. Let’s look at a salad. This salad is a mixture of lettuce, tomatoes, onion, olives, cucumbers, and cheese. Each time you took a different spoonful, it would be slightly different from all the others. The first spoonful might not have any olives, and another spoonful might not have any cheese. No matter how much you stir the salad, the individual ingredients of the salad do not change. Heterogeneous mixtures are generally easy to separate because the ingredients are usually large in size (can be seen with your eyes).