This book has been designed to provide fundamental knowledge of the principles related to environment and its chemistry so as to meet the challenging requirements of students, teachers as well as researchers of Environmental Sciences, Environmental Chemistry and Environmental Studies at graduate, postgraduate, polytechnic and engineering levels at all Indian Universities. It emphasizes that all living and nonliving parts of our environment are made up of chemicals and that all of the natural processes continuously occurring in the environment involve chemical reactions. The book tries to present the topics that are essential to understand the chemical process in our environment—involving air, Water and Soil. With this concept of interdependence, students begin to see that without some understanding of chemistry, it is impossible to fully understand environmental issues such as ozone depletion, global warming, air and water pollution and the hazards of radioactivity. This book is also useful for the students and teachers of general science.