The types of hybrid orbitals of nitrogen in NO₂⁺ , NO₃^- and NH₄⁺ respectively are expected to be
A. sp, sp³ and sp²

B. sp, sp² and sp³

C. sp², sp and sp³

D. sp², sp³ and sp

The number of orbitals involved in hybridization can be determined by the application of formula:

H = number of orbitals involved in hybridization
V= valence electrons of the central atom
M= number of monovalent atoms linked with the central atom
C = charge on the cation
A = charge on the anion

Thus, for NO₂⁺ H is 2 i.e. sp, for NO₃^- H is 3 i.e. sp² and for NH₄⁺ H is 4 i.e. sp³.