The values of EN of A and B are 1.2 and 4.0 respectively. % ionic character in bond A - B is
50%
43%
55.3%
72.24%
16[EA−EB]+3.5[EA−EB]2=% Ionic character
16[4.0−4.q]+3.5(4−1.2)2=% Ionic character
% Ionic character=72.24%