Periodic Law of Chemistry Overturns for Superheavy Elements

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.