Which of the following is the reason why sodium metal conducts electricity?

Comment on each of the following observations:
$(a)$ The mobilities of the alkali metal ions in aqueous solution are
$Li^{+} < Na^{+} < K^{+} < Rb^{+} < Cs^{+}$
$(b)$ Lithium is the only alkali metal to form a nitride directly.
$(c)$ $E^{\circ}$ for $M^{2+}_{(aq)} + 2e^{-} \longrightarrow M_{(s)}$ (where $M = Ca, Sr$ or $Ba$) is nearly constant.

$A$ chloride is soluble in cold water. When it is placed on a $Pt$ wire and heated in a Bunsen flame,it does not impart any characteristic color to the flame. Which of the following cations is present?

Oxygen gas can be prepared from solid $KMnO_4$ by

How do you account for the strong reducing power of lithium in aqueous solution?

Which of the following does not illustrate the anomalous properties of lithium?