Give plausible reason for the fact that the first ionization enthalpies of the $5d$-transition metals are higher than those of the $3\mathrm{d}$ and $4\mathrm{d}$ transition metals.

Explain why transition metals form:

alloys with other transition metals easily.

Explain why transition metals form:

compounds in different oxidation states.

Represent by ionic equation, the oxidising action of ${\mathrm{MnO}}_4^{-}$ both in acidic and alkaline media. Write the balanced chemical equation of ${\mathrm{SO}}_2$ and ${\mathrm{MnO}}_4^{-}$ in acidic medium.

Decide giving reasons which one of the following exhibits the property indicated:

(i) ${\mathrm{Sc}}^{3+}$ and ${\mathrm{Cr}}^{3+}$ Exhibits paramagnetism.

(ii) $\mathrm{V} \mathrm{or} \mathrm{Mn}$  Exhibit number of oxidation states (at. no. $\mathrm{Sc}=21, \mathrm{V}=23,\mathrm{Cr}=24,\mathrm{Mn}=25$)