Is Matter Around Us Pure? from NCERT Class IX Science explains the difference between pure substances and mixtures. It covers homogeneous and heterogeneous mixtures, solutions, suspensions and colloids, concentration of a solution, methods of separating the components of a mixture, and the difference between physical and chemical changes, elements and compounds. These free MCQ practice tests help you revise definitions, examples and separation techniques for class tests and school exams. Each short test is timed, scored instantly and followed by a full answer review.