The reactivity of $Na$ metal with water is utilized in which of the following processes?

When $Zn$ is treated with excess of $NaOH$,the product obtained is

As compared to lithium,sodium reacts quickly with water because

The reaction of an element $A$ with water produces a combustible gas $B$ and an aqueous solution of $C.$ When another substance $D$ reacts with this solution $C,$ it also produces the same gas $B.$ $D$ also produces the same gas even on reaction with dilute $H_2SO_4$ at room temperature. Element $A$ imparts a golden yellow color to the Bunsen flame. Then,$A, B, C,$ and $D$ may be identified as:

Which of the nitrates on strong heating leaves the metal as the residue?

The valence shell electronic configuration of alkali metals is