Atoms and Molecules from NCERT Class IX Science introduces the laws of chemical combination, Dalton's atomic theory, atoms and their symbols, atomic mass, molecules, ions, writing chemical formulae, molecular mass and the mole concept. It is the starting point for all the chemistry calculations you will meet in later classes. These free MCQ practice tests check both concepts and simple numericals, helping you prepare for class tests and school exams. Every test is timed, scored instantly and comes with a complete answer review.