This volume is a collection of the Nobel Lectures delivered by the prizewinners, together with their biographies, portraits and the presentation speeches at the award ceremonies in Stockholm for the period 1996 - 2000. Each Nobel Lecture is based on the work for which the laureate was awarded the prize. New biographical data of the laureates, since they were awarded the Nobel Prize, are also included. These volumes of inspiring lectures by outstanding chemists and biochemists should be on the bookshelf of every keen student, teacher and professor of chemistry as well as of those in related fields.Below is a list of the prizewinners during the period 1996-2000 with a description of the works which won them their prizes.(1996) R F CURL, Jr, H W KROTO & R E SMALLEY — for their discovery of fullerenes; (1997) P D BOYER & J E WALKER — for their elucidation of the enzymatic mechanism underlying the synthesis of adenosine triphosphate (ATP) and; J C SKOU — for the first discovery of an ion-transporting enzyme, Na+, K+-ATPase; (1998) W KOHN — for his development of the density-functional theory and; J A POPLE — for his development of computational methods in quantum chemistry; (1999) A H ZEWAIL — for his studies of the transition states of chemical reactions using femtosecond spectroscopy; (2000) A J HEEGER, A G MacDIARMID & H SHIRAKAWA — for the discovery and development of conductive polymers.