Which is most basic in character?

$Cs^{+}$ ions impart violet colour to Bunsen flame. This is due to the fact that the emitted radiations are of

Statement $A$: Extraction of magnesium is done by the electrolysis of a molten mixture of $MgCl_2$,$NaCl$,and $CaCl_2$.
Reason $R$: Calcium chloride acts as a reducing agent.

Magnesium burns in air to give

Write the outer electronic configuration of alkali metals. Discuss the justification for their position in group $1$ of the periodic table.

Which one of the following elements reduces $NaOH$ to $Na$?