The first two elements of period 8 are expected to be ununennium and unbinilium, elements 119 and 120. Their electron configurations should have the 8s orbital being filled. This orbital is relativistically stabilized and contracted and thus, elements 119 and 120 should be more like rubidium and strontium than their immediate neighbours above, francium and radium. Another effect of the relativistic contraction of the 8s orbital is that the atomic radii of these two elements should be about the same of those of francium and radium. They should behave like normal alkali and alkaline earth metals, normally forming + 1 and + 2 oxidation states respectively, but the relativistic destabilization of the 7p subshell and the relatively low ionization energies of the 7p electrons should make higher oxidation states like + 3 and + 4 (respectively) possible as well.
what is the atomic number of the yet undiscovered element directly below ra in the periodic table
120 120