In amines, the nitrogen atom is A and B hybridized, making geometry of amines as C. Then A, B and C respectively are:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → trivalent, \(sp^3\), pyramidal
Nitrogen in amines forms three σ bonds and keeps one lone pair, like nitrogen in ammonia. Four electron pairs need four sp3 orbitals; with one of them holding the lone pair the shape is pyramidal.
Why the other options are incorrect
Option (1) trivalent, \(sp^2\), trigonal — Incorrect. sp2 nitrogen with a trigonal planar shape would need the lone pair in an unhybridised p orbital; in amines it occupies an sp3 orbital.
Option (2) tetravalent, \(sp^3\), tetrahedral — Incorrect. Nitrogen becomes tetravalent and tetrahedral only in quaternary ammonium ions (\( \ce{R4N^{+}} \)), not in amines.
Option (4) tetravalent, \(sp^2\), pyramidal — Incorrect. Nitrogen in amines is not tetravalent, and sp2 hybridisation would give a planar, not pyramidal, shape.
NCERT (2026-27 edition):
Structure of Amines
