Question

Which of the following elements does not forms stable diatomic molecules :

• A. $I$
• B. $P$
• C. $N$
• D. $O$

Answer 1

Answer: (B)

$P$

Phosporous forms tetra atomic molecule it do not forms stable diatomic molecule where as the other given elements forms stable diatomic molecules(Due to larger atomic size P is do not form pi bonds and so it exists as a tetra-atomic moleculein which each P atom is bonded with 3 other P atoms by 3 sigma bond. But, due to smaller atomic size N forms 1 sigma and 2 pi bonds i.e. triple bonds with other N atom and exists as diatomic molecule.)
Hence option B is correct.