Which of the following elements has the highest electronegativity? beryllium iodine calcium nitrogen

Option (d) is the correct answer.

Explanation:

An atom or element which has the ability to readily gain an electron will have high electronegativity.

Both Beryllium and Calcium are alkaline earth metals and hence they are electropositive in nature.

Whereas both iodine and nitrogen are electronegative in nature. But across the period there is an increase in electronegativity and down the group there is a decrease in electronegativity.

Nitrogen belongs to period 2 and iodine belongs to the bottom of group 17. Thus, we can conclude that nitrogen is more electronegative than iodine.

The correct option is: D. nitrogen                    

Explanation:

Electronegativity is the capability of a chemical element to attract or pull the bond pair involved in the formation of a covalent bond towards itself.

As the atomic radius of an element increases, its tendency to attract the bond pair towards itself decreases. Therefore, the electronegativity decreases.

Since in the periodic table, the atomic radius increases down a group and generally decreases across a period. So, the electronegativity decreases down the group and generally increases across a period.

Therefore, Nitrogen which belongs to period 2 and group 15 of the periodic table, has the smallest atomic radius among the given chemical elements and thus is the most electronegative element (3.04 on the Pauling scale) among the given chemical elements.