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 எழுநூறு இருபது ஒன்று protons in its nucleus, and எழுநூறு இருபது ஒன்று electrons in its shells.