Understanding the factors which determine the rates and products of elementary reactions is of fundamental importance to chemists. This book provides a concise account of the dynamics and kinetics of elementary reactions in the gas phase, and is structured to emphasize the relationship between thermal rate coefficients and the microscopic mechanisms of chemical reactions. The theoretical framework necessary to predict the dynamics and kinetics of elementary reactions is introduced, and is illustrated by reference to numerous theoretical and experimental studies. Extensive references to other undergraduate texts are also provided and diagrammatic examples are provided throughout, making this an essential course aid for second, third and fourth year undergraduate students of chemistry. First year postgraduate students and academics in physical chemistry departments will also find this book interesting.