1
Nitrogen forms N2, but phosphorus does not form P2, however, it exists as P4, reason is
- triple bond present between phosphorus atoms
- p - p bonding is weak
- p - p bonding is strong
- multiple bonds form easily.
Answer
(2) p - p bonding is weak
Solution
As per NCERT, nitrogen is small and highly electronegative, so it forms strong p - p multiple bonds with itself ⇒ N N (diatomic N2).
⇒ Phosphorus atoms are larger, so the sideways overlap of their 3p orbitals is poor and p - p bonding is weak.
∴ Phosphorus forms single P–P bonds instead and exists as tetrahedral P4 molecules.
Answer: (2)
AIPMT 2001