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 επτακόσια είκοσι ένα protons in its nucleus, and επτακόσια είκοσι ένα electrons in its shells.