This book places oxygen on the center stage of chemistry in a manner that parallels the focus on carbon by 19th century chemists. One measure of the significance of oxygen chemistry is the greater diversity of oxygen-containing molecules than of carbon-containing molecules. One of the most important compounds is water, containing the properties of being a unique medium for biological chemistry and life, the source of all the dioxygen in the atmosphere, and the moderator of the earth's climate. Sawyer first introduces the biological origins of dioxygen and role of dioxygen in aerobic biology and oxidative metabolism, and in separate chapters discusses the oxidation-reduction thermodynamics of oxygen species, and the nature of the bonding for oxygen in its compounds. Additional chapters focus on the reactivities of specific oxygen compounds. The book will be of interest to chemists and biochemists, as well as graduate students, life scientists, and medical researchers.