Septbiunium (Sbu)

Septbiunium is the systematic name of the theoretical 721. element in the periodic table with a symbol of Sbu and atomic number of 721. Septbiunium, also known as element 721, has sjey­hundrað­og­tjúgo­ein protons in its nucleus, and sjey­hundrað­og­tjúgo­ein electrons in its shells.