Periodic law and system of chemical elements: 150 years from the date of discovery

The data concerning the formulation of the Periodic Law and certain graphic variants of its interpretation, proposed at different times for 150 years from the moment of the opening of this law, have been presented and discussed. It was stated that, despite the presence of a very significant (several hundred) number of these variants, only two tabular versions of the Periodic Table of chemical elements, namely, the so-called "short-periodic" proposed by Dmitri Mendeleev and the so-called "long-periodic" proposed by Alfred Werner (which was recommended in the fullness of time by the International Union of Pure and Applied Chemistry), received practical applications. A modification of the indicated tabular variants, aimed at overcoming their shortcomings, has been proposed. The question of the existence of the upper boundary of the Periodic System and the probable prospects for obtaining super-heavy elements with a nuclear charge of Z > 110, in particular a new category of them 5g-elements, has been also discussed.