Question

Nitrogen (atomic number $7$) and phosphorus (atomic number $15$) belong to the group $15$ of the Periodic Table. Write the electronic configuration of these two elements. Which of these will be more electronegative and Why?

Answer 1

The electronic configuration of nitrogen $N\left(7\right)=2,5$

Phosphorous $P\left(15\right)=2,8,5$

$N$ is more electronegative than $P$.

From top to bottom down a group, electronegativity decreases. This is because number of shell increases down a group, and thus there is an increased distance between the valence electrons and nucleus, or a greater atomic radius.