In certain properties,lithium differs from other alkali metals. The main reason for this is:

Which of the following is the most important factor in making lithium metal the strongest reducing agent?

Compound $A$ reacts with $NH_4Cl$ and forms a compound $B$. Compound $B$ reacts with $H_2O$ and excess of $CO_2$ to form compound $C$,which on reaction with saturated $NaCl$ solution forms sodium hydrogen carbonate. Compounds $A, B$ and $C$ are respectively:

Which of the following is the correct increasing order for the mentioned property?

Which metals upon heating in the presence of air followed by hydrolysis give ammonia?

Given below are two statements:
Statement $I$ : The $4f$ and $5f$-series of elements are placed separately in the Periodic table to preserve the principle of classification.
Statement $II$ : $S$-block elements can be found in pure form in nature.
In the light of the above statements,choose the most appropriate answer from the options given below :