Chemistry plays an important part in all of the other natural sciences, basic and applied. Plant growth and metabolism, the formation of igneous rocks, the role played by ozone in the atmosphere, the establishment of forensic evidence. Chemistry is the study of the nature, properties, and composition of matter. When natural science (the systematic knowledge of nature) seemed quite clearly divisible into the physical and biological sciences, with the former being comprised of physics, chemistry, geology and astronomy and the latter consisting of botany and zoology. The emergence of important fields to study such as oceanography, paleobotany, meteorology, pharmacy and biochemistry, have made it increasingly clear that the dividing lines between the sciences are no longer at all sharp. Chemistry, for instance, now overlaps so much with geology (thus we have geochemistry), astronomy (astrochemistry) and physics (Physical and analytical chemistry) that it is probably impossible to devise a really good modern definition of chemistry. Glossary and index have been provided at the end of the book for quick reference. Diagrams, figures and tables supplement the text for clear understanding. All the topics have been covered in a cogent and lucid style to help the reader grasp the matter easily.This textbook also caters to the requirement of the syllabus prescribed by various universities for undergraduate and postgraduate students pursuing these courses. It is also an essential reading for all students, studying engineering, biotechnology, microbiology, environment and for B.Sc. and M.Sc. (Pass) and (Hons.) courses. It is also a valuable source of information for teachers, professors and researchers involved with chemistry.