Question

Nitrogen forms stable $N_2$ molecule but phosphorus is converted to $P_4$ from $P_2$ because

• A. $p\pi -p\pi$ bonding is strong in phosphorus
• B. $p\pi -p\pi$ bonding is weak in phosphorus
• C. triple bond is present in phosphorus
• D. single $P-P$ bond is weaker than $N-N$ bond

Answer 1

Answer: (B)

$p\pi$ - $p\pi$ bonding in nitrogen is strong hence it can form triple bond with another $N$. Single $N-N$ bond is weaker than $P-P$ bond due to high interionic repulsion of non-bonding electrons. Hence, $N=N$ is stable and $P_2$ is not.