What is a mixture?

A mixture is a combination of two or more substances that are physically combined but not chemically joined. Each substance in a mixture retains its own properties and can be separated using suitable methods.

For example, a mixture of sand and salt contains both substances together, but they do not react with each other. Similarly, air is a mixture of gases like oxygen, nitrogen, and carbon dioxide.

Mixtures can vary in composition, meaning the proportion of each substance is not fixed. This is why the same type of mixture can look or behave differently depending on how it is prepared.

Understanding mixtures is important because most substances around us, whether in nature or daily use, exist in mixed forms rather than pure.