Why do alkali metals form blue coloured solution with NH₃?

Why sodium and potassium are not found in the native state?

What happens when a piece of sodium is put in water? Give also balanced equation for the reaction.

24.

Why sodium catches fire when dropped in water?

Name the alkali metals which form superoxides when heated in excess of air. 

Which of the following alkali metal is having least melting point?
(i) Na   (ii) K     (iii) Rb      (iv) Cs

Arrange the following in decreasing order of ionic character: MF, MCl, MBr, MI where M reprents a metal.

Name the method for the extraction of sodium metal.

What is electrolyzed in Down’s process to obtain sodium?