Salient features of the book: Keeping in mind the age group of the students, the matter has been divided into sections and sub-sections so that the students can learn at their own pace. All new concepts have been developed by class-activity method. The practical hand-on experience of these activities will enable the students to visualize and develop a deeper understanding of the concepts. Results, wherever possible, have been verified by lab activity method. Questions in the form of Fill in the blanks, True/False statements and Multiple Choice Questions, given under the heading ‘Mental Maths’, Have been added for the objective assessment of the concepts. In addition to standard questions, some Higher Order Thinking Skills (HOTS) questions have been included to enhance the analytical thinking of the students. Each chapter is followed by a Summary which recapitulates the new terms, concepts and results. The last section ‘Check Your Progress’, acts as a Unit Test. Model Question Papers, given at various places, will serve as means for revision and preparation for the exam.