In an octahedral crystal field,the $t_{2g}$ orbitals are:

Which of the following spectrochemical series is correct?

Assertion : Potassium ferrocyanide is diamagnetic,whereas potassium ferricyanide is paramagnetic.
Reason : Crystal field splitting in ferrocyanide ion is greater than that of ferricyanide ion.

Match List-$I$ with List-$II$:

List-$I$ (Complex)	List-$II$ ($CFSE$ in $\Delta_0$)
$A$. $[Ti(H_2O)_6]^{2+}$	$I$. $-1.2$
$B$. $[V(H_2O)_6]^{2+}$	$II$. $-0.8$
$C$. $[Mn(H_2O)_6]^{3+}$	$III$. $-0.6$
$D$. $[Fe(H_2O)_6]^{3+}$	$IV$. $0$

The octahedral complex of a metal ion $M^{3+}$ with four monodentate ligands $L_1, L_2, L_3$ and $L_4$ absorb wavelengths in the region of red,green,yellow and blue,respectively. The increasing order of ligand strength of the four ligands is:

The number of unpaired electrons in the complex ion $[CoF_6]^{3-}$ is (Atomic number of $Co = 27$).