The $Cs^{+}$ ion imparts a violet color to the flame. This is due to the fact that the emitted radiation has .........

On heating to $400-500\,^oC$,relatively unstable hydrides and carbonates decompose. Which of the following will decompose when heated to $400-500\,^oC$ ?
$(I) \ LiH$ $ $ $(II) \ NaH$ $ $ $(III) \ Li_2CO_3$ $ $ $(IV) \ Na_2CO_3$

Give brief explanations on hydroxides of alkali metals.

Which of the following statements is incorrect?

Explain the biological importance of sodium and potassium.

$Na_2CO_3$ is prepared by the Solvay process, but $K_2CO_3$ cannot be prepared by the same process because: