Hexennunium (Heu)

Hexennunium is the systematic name of the theoretical 691e element in the periodic table with a symbol of Heu and atomic number of 691. Hexennunium, also known as element 691, has zes­honderd­een­en­negentig protons in its nucleus, and zes­honderd­een­en­negentig electrons in its shells.