Octquadnilium (Oqn)
Octquadnilium is the systematic name of the theoretical 840. element in the periodic table with a symbol of Oqn and atomic number of 840. Octquadnilium, also known as element 840, has kahdeksansataaneljäkymmentä protons in its nucleus, and kahdeksansataaneljäkymmentä electrons in its shells.