Write the hybridisation and number of unpaired electrons in the complex [CoF6]³⁻. (Atomic No. of Co=27)

[CoF6]³⁻ is an octahedral complex in which the central Co atom is sp³d² hybridised. Outer 4d orbital is utilized in hybridisation. Hence, it is an outer orbital or high spin or spin free complex. Due to the presence of four unpaired electrons, [CoF6]³⁻ is paramagnetic.