In formation of sulphurous acid, sulphur atom is in

In the oxoacids of sulphur in which sulphur is tetravalent with an oxidation state of '+4' (or) '+3'Sulphur atom will be in I - excited stateSulphur(Z=16) -  Ground state configuration isI - excited state configuration isSulphur  atom has a lone pair and forms 3 σsp3-pbonds with oxygen atoms;It forms one πd-pbond with oxygen atom;