Assertion(A) :  On reaction with liquid ammonia, alkali metals give conducting solution
Reason(R) : Ammoniated ${\text{e}}^{-}$  and ammoniated cations are formed when alkali metals is present in liquid ammonia.

All alkali metals dissolve in liquid ammonia and give deep blue colour solution which are conducting in nature. These solutions contain ammoniated cation and ammoniated electrons
$M+(x+y)N{H}_3\to {\left[M{\left(N{H}_3\right)}_x\right]}^{+}+{\left[e{\left(N{H}_3\right)}_y\right]}^{-}$
The electrical conductivity of the solution is due to both ammoniated cations and ammoniated electrons.