As compared to lithium,sodium reacts more quickly with water because:

What is the correct order of ionic mobility for alkali metal ions in an aqueous medium?

Match List-$I$ with List-$II$:

List-$I$ (Salt)	List-$II$ (Flame colour wavelength)
$(a)$ $LiCl$	$(i)$ $455.5 \text{ nm}$
$(b)$ $NaCl$	$(ii)$ $670.8 \text{ nm}$
$(c)$ $RbCl$	$(iii)$ $780.0 \text{ nm}$
$(d)$ $CsCl$	$(iv)$ $589.2 \text{ nm}$

Choose the correct answer from the options given below:

When heated in air,the alkali metals form various oxides. Mention the oxides formed by $Li$,$Na$ and $K$.

Nitre is

$A$ metal $M$ reacts with nitrogen gas to afford $M_3N$. $M_3N$ on heating at high temperature gives back $M$ and on reaction with water produces a gas $B$. Gas $B$ reacts with aqueous solution of $CuSO_4$ to form a deep blue compound. $M$ and $B$ respectively are