Question

how to know the lone pair in formal charge​

Answer 1

ANSWER:-

Formal charge = [ # valence electrons on neutral atom] - [ (# lone electron pairs)+ ( 1/2 # bonding electrons) ] .

valence electrons :- corresponds to the group number of the periodic table( for representative elements ).

lone pairs :- Lone electrons setting on the atom . each electron counts as one and so a pair counts as two.