Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: $$\mathrm{LiF}$$ is sparingly soluble in water.

Reason R: The ionic radius of $$\mathrm{Li}^{+}$$ ion is smallest among its group members, hence has least hydration enthalpy.

In the light of the above statements, choose the most appropriate answer from the options given below.

Reaction of $$\mathrm{BeCl}_{2}$$ with $$\mathrm{LiAlH}_{4}$$ gives :

(A) $$\mathrm{AlCl}_{3}$$

(B) $$\mathrm{BeH}_{2}$$

(C) $$\mathrm{LiH}$$

(D) $$\mathrm{LiCl}$$

(E) $$\mathrm{BeAlH}_{4}$$

Choose the correct answer from options given below :

The correct order of density is :

Choose the correct order of density of the alkali metals :