Explain electronegativity of group 13 elements.

Explanation

Group 13 elements are more electronegative than the elements of group 1 and 2 . The electronegativity first decreases from boron to aluminium and then increases marginally down the group because atomic size increase . After aluminium due to the imperfect shielding effect of the d and f electrons the force of attraction of the nucleus towards electrons increases hence electronegativity increases .