The Periodic Law is one of the greatest discoveries in human history. Chemical elements in the same group of the Periodic Table possess similar valence states and other physico-chemical properties. With the increase of atomic number Z, the relativistic effects become so strong that the super-heavy elements tend to exhibit properties notably different from their lighter congeners. Here we report that the traditionally mono- or di-valent heavy s-block elements (87Fr, 88Ra, 119E, 120E) exhibit unusual penta- or hexa-valency at ambient conditions. Due to common quantum-mechanical and relativity effects, some atomic-core electrons of the heaviest s-block elements become sufficiently activated for chemical bonding, so that they no longer behave as strictly low-valent alkali and alkaline-earth elements. The classic Periodic Law discovered by Mendeleev and others since the 1860s has thus broken down for such super-heavy elements and beyond.
Supplementary Information for Periodic Law of Chemistry Overturns for Superheavy Elements