The following is the periodic table containing 172 elements, plus neutronium. The 218-element periodic table was suggested by Glenn T. Seaborg in 1969 based on non-relativistic model. Only 118 elements have been observed and the rest are hypothetical. Elements with atomic numbers 113, 115, 117–172 are not [officially] named yet (official names have been proposed for 113, 115, 117 and 118, although they will not come into effect until November), but they are systematically named and symbolled. However, this periodic table contains proposed and fabricated names and symbols for these elements as of 19 March 2013, all after prominent scientists (especially chemists and physicists), except 115 (after a science fiction author), 117 and 118 (after places).