Question

Which of the following has maximum non metallic character?
A) F
B) Cl
C) Br
D) I

Answer 1

Hint: Consider the trends in the ionization energy, on moving from top to bottom in the periodic table. With decrease in the ionization energy, the non metallic character decreases. Metallic character is associated with electropositive behavior and non metallic character is associated with electronegative behaviour.

Complete answer:
> In the periodic table, on moving from left to right, the metallic character decreases and the non metallic character increases. This is because the ionization energy increases on moving from left to right in a period.
> Metals have low ionization energy and non metals have high ionization energy.
> Similarly, in a group, on moving from top to bottom, the ionization energy decreases. Hence, non metallic character decreases and metallic character increases. Thus, fluorine and chlorine are non metals whereas iodine has metallic properties.
> Among all the elements in the periodic table, fluorine is the most electronegative element. It has a very high value of electronegativity. This results in high ionization enthalpy
> Among the halogens, fluorine has maximum non-metallic character.

Hence, option A ) is the correct option.

Note: As one moves down the group of halogen family, additional electron shells are added. The attraction between the nucleus and the outermost electron decreases. Atomic size increases and the ionization energy decreases. Due to this, the non-metallic character decreases and the metallic character increases.