The fundamental concepts are subtle and complex. In a unified General Chemistry text it is virtually impossible to delineate all significant facets of the subject. The present series was conceived with this objective in mind. In this series our main thrust is on the breadth of development of the subject and attention to detail. In the present volume our principal objective is to instruct beginners in modem views of the Chemical Bond. The development of the wave mechanics necessitated a fundamental change in Sidwick's electronic theory of valence. The development of molecular orbital method has resulted in a great enlightenment of the nature of chemical bonding. We have attempted to connect the course of these developments. This volume is intended to cater to the needs of students majority in chemistry. It will also serve as a handy reference for higher level students as well as teachers.