Resumen de The Different Periodic Tables of Dmitrii Mendeleev.
Between 1869 and 1905 the Russian chemist Dmitrii Mendeleev published several tables with different arrangements of the chemical elements. Four of these are compared with periodic tables by Russian scientists from 1934 and 1969. The difficulties caused by the lanthanoid elements are clearly seen in the table of 1905, which satisfactorily includes the inert gases. The Memorial Table of 1934 is based on atomic number, and correctly places both the inert gases and the lanthanoids.
