Question

Account for the following . n-n single bond is weaker than p-p single bond

Answer 1

Answer:

Explanation:

Due to the small size of nitrogen atom the incoming  electrons experience inter -electronic repulsion from the electrons of nitrogen atom which does not occur in phosphorus due to its large size.

Answer 2

Answer:

here it is

Explanation:

N−N single bond is weaker than P−P bond due to smaller size of N as compared to P. Smaller size of N leads to smaller N−N bond length. As a result, the lone pair of electrons on the both the N atoms repel each other leading to unstability or weakening of N−N bond.