The set of elements which obey the general electronic configuration $(n-1)d^{1-10}ns^2$ is

Identify the element having the highest ionization enthalpy among the given options.

Why is the $E^{\Theta }$ value for the $Mn^{3+}/Mn^{2+}$ couple much more positive than that for $Cr^{3+}/Cr^{2+}$ or $Fe^{3+}/Fe^{2+}$? Explain.

Which elements of the $3d$ series do not show variable valency?

Elements $A$ and $B$ do not form an alloy because....

Most transition metals exhibit several characteristic properties. Which of the following statements are correct?
$I$: Form sets of compounds which display different oxidation states of the metal.
$II$: Form coloured ions in solution.
$III$: Burn vigorously in oxygen.
$IV$: Act as catalysts.