Which of the following pairs of ions are colored in their aqueous solution?

For $M^{2+} / M$ and $M^{3+} / M^{2+}$ systems,the ${E^{\Theta}}$ values for some metals are as follows:
$Cr^{2+} / Cr : -0.9 \ V$
$Cr^{3+} / Cr^{2+} : -0.4 \ V$
$Mn^{2+} / Mn : -1.2 \ V$
$Mn^{3+} / Mn^{2+} : +1.5 \ V$
$Fe^{2+} / Fe : -0.4 \ V$
$Fe^{3+} / Fe^{2+} : +0.8 \ V$
Use this data to comment upon:
$(i)$ The stability of $Fe^{3+}$ in acid solution as compared to that of $Cr^{3+}$ or $Mn^{3+}$ and
$(ii)$ The ease with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.

Highest $(+7)$ oxidation state is shown by

Match the following elements in List-$I$ with their respective groups in List-$II$.

List-$I$ (Elements)	List-$II$ (Group)
$A$. $Mn, Tc, Re$	$IV$. $7$
$B$. $Zn, Cd, Hg$	$I$. $12$
$C$. $Ti, Zr, Hf$	$II$. $4$
$D$. $Ga, In, Tl$	$V$. $13$

The correct answer is:

Among the following components of cement,which is present in the highest amount?

The magnetic moment of $Mn^{4+}$ ion is approximately ...... $B.M.$