The book has been thoroughly revised according to the latest guidelines and syllabus prescribed by the Central Board of Secondary Education, New Delhi. The subject matter contained in this book has been explained in a simple language and includes many examples from real life situations. Emphasis has been laid on basic facts, terms, principles, concepts and on their applications. Carefully selected examples consist of detailed step-by-step solutions so that students get prepared to tackle all the problems given in the exercise. Salient features of the book: To fulfill the requirements of the teachers and the students in the best manner possible, the matter has been divided into sections and sub-sections. Consequently, the students will be able to learn at their own pace. Various new concepts have been developed with the help of class activity method. Questions in the form of Fill in the blanks, True/False Statements, Multiple Choice Questions, Assertion-Reason type and Case-Study Questions have been given. Multiple choice and Assertion-Reason Type Questions have been framed in a manner such that they holistically cover all the concepts covered in each chapter and also, prepare students for the competitive exams. A ‘Chapter Test’ has been put in the end of each chapter which serves as the brief revision of the entire chapter. The book contains sufficient number of solved examples to meet the needs of all categories of students.