The hybridization Nitrogen in NO2+,NO3− and NH4+ is, x,y,z. Then x,y,z hybridization can be

For NO2+:H=12(5+0+0−2)=2: ∴sp hybridizationFor NO3−:H=12[5+0+1−0]=3;∴sp2 hybridizationFor NH4+:H=12[5+4+0−1]=4:∴sp3 hybridization