Essentials of Chemistry: General, Organic, and Biochemistry, Volume I provides students with a brief yet complete guide to foundational knowledge and concepts in chemistry. The opening chapter discusses the atom, with content on atomic theory, elements and nuclides, substances and mixtures, energy changes, and more. Additional chapters address chemical elements and the periodic table, bonds and compounds, chemical changes, chemical calculations, and aqueous solutions. Students learn about the states of matter; acids, bases, and salts; and nuclear chemistry. The closing chapter presents an introduction to organic chemistry. Each chapter features a Threads from Previous Chapters section that highlights information from previous chapters that is necessary for full comprehension of the present chapter; a Setting the Stage section to prepare students to learn; learning objectives; a chapter summary; skill-check exercises; and end-of-chapter concept reviews. Appendices at the back of the book provide solutions to odd problems for all problem sets throughout the text. Essentials of Chemistry is the first textbook in a two-volume series designed to help students learn and apply critical information and skillsets within the discipline.