Question

At $25^{o}C$ , nitrogen exists as $N_2$ and phosphorous exists as $P_4$ because

• A. $N_2$ has valence electrons only in bonding and non-bonding orbitals, while $P_4$ has valence electrons in both bonding and anti bonding orbitals
• B. higher electronegativity of nitrogen favours formation of multiple bonds
• C. bigger size of phosphorus does not favour multiple bonds
• D. phosphorus has preference to adapt structures with small bond angles

Answer 1

Answer: (C)

Due to larger atomic size $\text{P}$ is unable to form pi bond and so it is tetra-atomic $\left(P_4\right)$ in which each $\text{P}$ atom is linked with $\text{3}$ other $\text{P}$ atoms by $\text{3}$ sigma bonds. But, due to smaller atomic size $\text{N}$ forms $\text{1}$ sigma and $\text{2}$ pi bonds i.e. triple bonds with other $\text{N}$ atom and exists as diatomic molecule $\left(N_2\right)$ .