........ રજૂ કરે છે.
$(i)$ $[Ni(CO)_4], \,sp^3$
$(ii)$ $[Ni(CN)_4]^{2-}, \,sp^3$
$(iii)$ $[CoF_6]^{3-}, \,d^2sp^3$
$(iv)$ $[Fe(CN)_6]^{3-}, \,sp^3d^2$
$\left( {{C_2}O_4^{2 - } = } \right.$ ઓક્ઝલેટો $)$