The coordination complex $[Co(OH_2)_6]^{2+}$ has one unpaired electron. Which of the following statements are true?
$(i)$ The complex is octahedral.
$(ii)$ The complex is an outer orbital complex.
$(iii)$ The complex is diamagnetic.

$A$ list of species having the formula $XZ_4$ is given below.
$XeF_4, SF_4, SiF_4, BF_4^-, BrF_4^-, [Cu(NH_3)_4]^{2+}, [FeCl_4]^{2-}, [CoCl_4]^{2-}$ and $[PtCl_4]^{2-}$.
Defining shape on the basis of the location of $X$ and $Z$ atoms,the total number of species having a square planar shape is

Which of the following complexes exhibits square planar geometry?

How many unpaired electrons are present in the central metal ion of $[CoCl_4]^{2-}$?

The hexafluoroferrate$(III)$ ion is an outer orbital complex. The number of unpaired electrons in it is.....

Which of the following sequences of hybridisation, geometry, and magnetic nature are correct for the given coordination compounds?
$A.$ $[NiCl_4]^{2-}$ – $sp^3$, tetrahedral, paramagnetic  
$B.$ $[Ni(NH_3)_6]^{2+}$ – $sp^3d^2$, octahedral, paramagnetic  
$C.$ $[Ni(CO)_4]$ – $sp^3$, tetrahedral, paramagnetic  
$D.$ $[Ni(CN)_4]^{2-}$ – $dsp^2$, square planar, diamagnetic  
Choose the correct answer from the options given below: