Which of the following graphs is the correct representation of the relationship between atomic number $(Z)$ and the magnetic moment of $d-$block elements? [Outer electronic configuration : $(n - 1)d^x\ ns^{1\ or\ 2}$]

Which of the following elements does not form an amalgam?

Which one of the following ions will be colourless in an aqueous solution? (Atomic numbers: $Sc = 21, Fe = 26, Ti = 22, Mn = 25$)

The $E^{\circ}$ value for the $Mn^{3+} / Mn^{2+}$ couple is more positive than that of $Cr^{3+} / Cr^{2+}$ or $Fe^{3+} / Fe^{2+}$ due to change of

Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following points:
$(i)$ electronic configurations,
$(ii)$ oxidation states,
$(iii)$ ionisation enthalpies,and
$(iv)$ atomic sizes.

Which pair of metal ions from the following has the same number of unpaired electrons?