Broad in scope, this book describes the general theory and practice of using the Electron Capture Detector (ECD) to study reactions of thermal electrons with molecules. It reviews electron affinities and thermodynamic and kinetic parameters of atoms, small molecules, and large organic molecules obtained by using various methods. * Summarizes other methods for studying reactions of thermal electrons with molecules * Discusses applications in analytical chemistry, physical chemistry, and biochemistry * Provides a data table of electron affinities