Is Matter Around Us Pure?

The chapter “Is Matter Around Us Pure?” from NCERT Science Class 9 explains that most substances around us are not pure but exist as mixtures of different components. A pure substance is made up of only one type of particle, such as elements (like oxygen or gold) or compounds (like water), and has fixed properties. In contrast, mixtures contain two or more substances physically combined and can be homogeneous (uniform, like salt solution) or heterogeneous (non-uniform, like sand in water). The chapter also discusses methods of separating mixtures—such as filtration, evaporation, and distillation—and introduces the idea that purity in science refers to having a single type of particle, not just being “clean” in everyday terms.