$d^2sp^3$ hybridisation leads to

Which of the following complexes exhibits $sp^{3}d$ hybridization?

Which of the following metal carbonyl complexes is correctly matched with its magnetic property and geometry?

For octahedral $Mn(II)$ and tetrahedral $Ni(II)$ complexes,consider the following statements:
$(I)$ Both the complexes can be high spin.
$(II)$ $Ni(II)$ complex can very rarely be low spin.
$(III)$ With strong field ligands,$Mn(II)$ complexes can be low spin.
$(IV)$ Aqueous solution of $Mn(II)$ ions is yellow in color.

$Cu^{2+}$ shows a coordination number of

In which of the following complex ions is the central metal atom's $d$-orbital devoid of electrons?