From which of the following minerals is $Ra$ (Radium) obtained?

Thermal decomposition of sodium nitrate at temperatures above $800\,^oC$ yields ..........

In which of the following processes,fused sodium hydroxide is electrolysed at a $330 \ ^oC$ temperature for the extraction of sodium?

The colour given to the flame by sodium salts is

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

The alkali metals form salt-like hydrides by direct synthesis at elevated temperatures. The thermal stability of these hydrides decreases in which of the following orders?