Pentquadennium (Pqe)
Pentquadennium is the systematic name of the theoretical 549. element in the periodic table with a symbol of Pqe and atomic number of 549. Pentquadennium, also known as element 549, has piecsimt četrdesmit deviņi protons in its nucleus, and piecsimt četrdesmit deviņi electrons in its shells.