The NCERT questions given at the end of each chapter are not only important for examinations but also helpful to clearly understand all the concepts. That is why students are strongly recommended to ...

NCERT books are the first preference to prepare for CBSE and competitive exams. Class 9 is the foundation builder for students so they need to develop a strong conceptual foundation for higher studies ...

Explanation: A pure substance is one which is made up of only one kind of atoms or molecules. They have the same composition throughout. 2.Rusting of an article made up of iron is called (a) corrosion ...