Question

An element X belongs to the second period and group 15 of the periodic table. Find out

(i) the number of valence electrons in its atoms. 

(ii) valency of the elements.

Answer 1

(i) Since the element belong to the 15^th group , so it must have 5 valence electrons in its atoms. 

(ii) since the element is in 2^nd period and belongs to 15^th group, so it must be nitrogen. Nitrogen has a valency of 3.