The electronic configuration of $Cs$ is

Which alkali metals are useful as electrodes in photoelectric cells?

State the reasons for the following:
$(a)$ Why is a solution of $Na_{2}CO_{3}$ alkaline?
$(b)$ Why are alkali metals prepared by the electrolysis of their fused chlorides?
$(c)$ Why is sodium found to be more useful than potassium in biological systems?

Which is most basic in character?

Identify the product when magnesium burns in air.

Which metal has a greater tendency to form metal oxide?