The book is an attempt to briefly describe the chemical elements and their stable and radioactive isotopes – from the Big Bang, the initial synthesis of the lightest elements in space, to the subsequent and ongoing nuclear reactions in stars for the synthesis of heavier elements. It describes the efforts of scientists to systematize the chemical elements according to their masses (weights) and properties, culminating in Dmitri Ivanovich Mendeleev's brilliant creation – the Periodic Law of Chemical Elements. Separate articles for each of the 118 elements present the stories of their discovery or synthesis on Earth, describing their properties and applications. A number of phenomena, processes, and experiments related to the elements, their compounds, and their isotopes are presented. Research on determining some properties of synthesized superheavy elements with lifetimes of seconds is also included, using the original method of Czech scientist Ivo Zvara at JINR, Dubna. This method makes it possible to study the elements as they are produced atom by atom.