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 שבע מאות עשרים ואחת protons in its nucleus, and שבע מאות עשרים ואחת electrons in its shells.