The collection contains articles by famous Soviet physicists and chemists, academicians of the USSR Academy of Sciences B. M. Kedrov, V. A. Fok, academician of the Academy of Sciences of the BSSR M. A. Elyashevich and others. These articles are devoted to the most important areas related to the development of the theory of the structure of an atom and its influence on the development of modern ideas about the essence of the law of periodicity and the system of elements.