Question

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

Answer 1

Electronic configuration of nitrogen (atomic number 7) :
Shells:      K L
Electrons: 2 5

Electronic configuration of phosphorus (atomic number 15) :
Shells:      K L M
Electrons: 2  8  5

The element nitrogen will be more electronegative because of the smaller size of its atom compared to phosphorus. Since, nitrogen has a smaller atomic radius than phosphorus, the attraction of its nucleus towards the incoming electron is more than phosphorus. Therefore, nitrogen accepts electrons more easily.