Har Simrat Singh13 Years agoin co ord compounds hybridisations of three types exist (mostly) sp3 dsp2 and sp3d2 ni z= 28 3d8 4s2 oxidation state 0 CO is neutral ligand and strong field ligand therefore e- pairing occurs and final e- config after pairing is 3d10 4s0 hence 4s and 4p orbitals will be used for bonding and no of ligand is 4 so hybridisation sp3