Question

How do electronegativity vary in a group and period explain?

Answer 1

Answer:

Electronegativity decreases down the group.

Electronegativity increases from left to right along the period.

Explanation:

As we move down the group, in the periodic table, the electrons are added to the next, shell or level(valence shell), thus reducing the internuclear attraction of nucleus towards the valence electrons added to the valence shell and they have large size. Thus the atom or element will poorly try to attract or distort electrons from other atom towards itself, since they have high size and poor internuclear attraction.

Whereas, as we move from left to right along a period, the electrons are added to the same level or shellhigher through out that entire period. Thus the size reduces as we move from left to right along a period.

Therefore, the atom or elements have higher or better internuclear attraction to distort an electron of another atom towards itself.

Thus, along the period, from left to right, electronegativity increses.

Fluorine is the most electronegative element in the periodic table, with electronegativity value of 4.