The basic strength of the hydrides of group 15 elements :

Options

A. decreases on moving down the group
B. increases on moving down the group
C. first decreases upto `AsH_(3)` and then increases
D. first increases upto `AsH_(3)` and then decreases

Answer

A

Explanation

The basic strength of the hydrides of group 15 elements down the group decreases because down the group as electronegativity decreases `p`-orbital take part in the bond and lone pair present in `s`-orbital : `s`-orbital is larger and non directional hence it has less effective tendency of bond formation.