The book is a source of fundamental knowledge about the structure of the periodic system of elements and consistently explains both the basic information about all chemical elements and the patterns of changes in their properties in it. Throughout history, attempts have been made repeatedly to systematize chemical elements in order to find certain regularities, but these attempts have not always been successful. Eventually, the form of the periodic table proposed by D.I. Mendeleev became the most common and accepted, which is still used today. It is known that chemical elements are located in the periodic system according to certain patterns, taking into account the charge of the atomic nucleus, atomic mass, electronegativity, ionization energy, the metallic nature of the element and the basicity of oxides. Understanding the trends in these characteristics in the periodic system allows you to predict the properties of a particular element and also provide for the course of certain chemical reactions. The special feature of the book is that it describes the astrophysics of elements, and also provides basic information about reactions that take place in stars or interstellar space. The book is not overloaded with chemical equations, so it is suitable for those who want to acquire fundamental knowledge about the elements, as well as for those who want to expand their horizons.