Why does electronegativity decrease down a family?

A: The sizes of the atoms increase.

B: The sizes of the atoms decrease.

C: The total positive charge increases.

D: The total positive charge decreases.

Oprtion - A: (The sizes of the atoms increase) is the correct answer.

Explanation:

Electronegativity is defined as the ability of an atom to attract the bonded pair electrons toward itself. On a Pauling scale Fluorine is assigned the greatest electronegativity of 4.

Trend in Group:

Moving down the group the number of shells increases. Therefore, the number of core electrons increases which results in shielding the valence or bond pair electrons. Hence, electrons will be less attracted by the nucleus.