In thermodynamics and physical chemistry, thermochemistry is the study of the heat evolved or absorbed in chemical reactions. Thermochemistry, generally, is concerned with the heat exchange accompanying transformations, such as mixing, phase transitions and chemical reactions. This book presents leading research from around the world in this important field. Recent developments in the thermochemistry of pre-nucleation clusters are discussed, as well as the atmospheric implications of the new thermochemical data. Furthermore, plasma surface treatments are widely used in industrial applications. Thus, thermochemical processes assisted by plasma in the manufacturing sector are presented. Also discussed in this book are other advances in the field of chemistry, including the effect of nanostructure on the optical properties of earth ions.