This book is an outgrowth of the authors' sense that the topics covered by the majority of traditional engineering thermodynamics texts have evolved only slightly over the last several decades. The age of "molecular manufacturing" is here, and it is important that molecular concepts be emphasized in thermodynamics texts. Unique chapters on statistical mechanics, polymers, and surface thermodynamics support this viewpoint. The text is meant to provide students with the foundations that will allow them to apply concepts from thermodynamics to a wide range of problems. A postulatory approach is adopted, in which concepts such as entropy and free energy arise as simple mathematical functions that facilitate a description of the problem at hand.