Question

Assertion (A): The basic nature of VA group hy-drides decreases from ammonia to bismuthine.
Reason (R): Availability of lone pair on the cen-tral atom in hydrides decreases down the group.

• A. Both (A) and (R) are true and (R) is the correct
  explanation of (A)
• B. Both (A) and (R) are true and (R) is not the
  correct explanation of (A)
• C. (A) is true and (R) is false
• D. (A) is false but (R) is true

Answer 1

The correct option is A Both (A) and (R) are true and (R) is the correct

explanation of (A)
N has small size so less volume more electron density. As we move down the group availability of lone pair decreases. Therefore basic nature of hydrides decreases.