The total number of unpaired electrons present in the complex $K_3[Cr(C_2O_4)_3]$ is ..........

In $Cr^{2+}, Mn^{2+}, Fe^{2+},$ and $Ni^{2+}$,the number of electrons in the $3d$ orbital are $3d^4, 3d^5, 3d^6,$ and $3d^8$ respectively. Which of the following aqueous complexes will have the lowest magnetic moment?

$[Co(NH_3)_4(NO_2)_2]Cl$ exhibits

Among the following,the pair of paramagnetic complexes is

The correct order of the number of unpaired electrons in the given complexes is
$A$. $[Fe(CN)_6]^{3-}$; $B$. $[FeF_6]^{3-}$; $C$. $[CoF_6]^{3-}$; $D$. $[Cr(oxalate)_3]^{3-}$; $E$. $[Ni(CO)_4]$
Choose the correct answer from the options given below:

Arrange the following coordination compounds in the increasing order of magnetic moments. (Atomic numbers: $Mn = 25$; $Fe = 26$)
$(A)$ $[FeF_{6}]^{3-}$
$(B)$ $[Fe(CN)_{6}]^{3-}$
$(C)$ $[MnCl_{6}]^{3-}$ (high spin)
$(D)$ $[Mn(CN)_{6}]^{3-}$