Some reflections on periodic tables, somewhat periodic and not at all periodic

Abstract

In 2019, the 150th year of the publication of Mendeleyev’s periodic table has been celebrated. Its form and content has evolved but fundamentally, sorting them elements according to properties and similarities of chemical behaviour, have been maintained. There have been acts, publications, etc. sometimes with little to do with chemistry just sorting itself according to one of the typical forms of the table, but without justification, especially ignoring the periodicity of properties. This work discusses some of these cases and proposes some examples.