Match the complex ion (in List-$I$) with the number of unpaired electrons (in List-$II$):

List-$I$	List-$II$
$A$. $[Fe(H_2O)_6]^{2+}$	$P$. $0$
$B$. $[Fe(H_2O)_6]^{3+}$	$Q$. $1$
$C$. $[Fe(CN)_6]^{4-}$	$R$. $2$
$D$. $[Fe(CN)_6]^{3-}$	$S$. $4$
$E$. $[Ni(H_2O)_4]^{2+}$	$T$. $5$

$CoSO_{4}Cl \cdot 5NH_{3}$ exists in two isomeric forms '$A$' and '$B$'. Isomer '$A$' reacts with $AgNO_{3}$ to give white precipitate,but does not react with $BaCl_{2}$. Isomer '$B$' gives white precipitate with $BaCl_{2}$ but does not react with $AgNO_{3}$. Answer the following questions.
$(i)$ Identify '$A$' and '$B$' and write their structural formulas.
$(ii)$ Name the type of isomerism involved.
$(iii)$ Give the $IUPAC$ name of '$A$' and '$B$.'

Given below are two statements:
Statement-$I$: $[Fe(ox)_3]^{3-}$ is chiral.
Statement-$II$: $trans-[Cr(H_2O)_2(ox)_2]^-$ is chiral.
(Given: $oxH_2 = HOOC-COOH$)
In light of the above statements, choose the most appropriate answer from the options given below:

For a metal ion,the calculated magnetic moment is $4.90 \ BM$. This metal ion has $........$ number of unpaired electrons.

Explain the magnetic properties of coordination compounds.

Among the following,the coloured compound is: