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 septyni šimtai dvidešimt vienas protons in its nucleus, and septyni šimtai dvidešimt vienas electrons in its shells.