Flerovium is the heaviest known member of group 14 in the periodic table, below lead, and is projected to be the second member of the 7p series of chemical elements. Nihonium and flerovium are expected to form a very short subperiod corresponding to the filling of the 7p1/2 orbital, coming between the filling of the 6d5/2 and 7p3/2 subshells. Their chemical behaviour is expected to be very distinctive: nihonium's homology to thallium has been called "doubtful" by computational chemists, while flerovium's to lead has been called only "formal".