(a)
$\left\lbrack NiCl_{4} \right\rbrack^{2 -}\$has tetrahedral shape. In this complex, Ni is in the +2 oxidation state and $Ni^{2 +}\$ion always forms tetrahedral complexes
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.