If electronegativity of A is 2.0 and that of B is 3.0, what is the covalent character percentage of the bond A-B?

The Hanny-Smith equation for the ionic character can be used in this case.

$16\left(\right|{\mathrm{x}}_{\mathrm{A}}-{\mathrm{x}}_{\mathrm{B}}\left|\right)+3.5{({\mathrm{x}}_{\mathrm{A}}-{\mathrm{x}}_{\mathrm{B}})}^2$

where 'x_A ' is the electronegativity of one element and x_B is the electronegativity of the other element.

Here, x_A is 2.0 and x_B is 3.0.

So, 16(|2−3|)+3.5(2−3)² = 16 + 3.5 = 19.5 %

The bond A-B has a 19.5% ionic character.