$CaCO_3$ $\xrightarrow[excess \ H_2O]{CO_2 \ in} A$ $\xrightarrow{\Delta} B$
Identify $A$ and $B$.

Given below are two statements:
Statement $I$: None of the alkaline earth metal hydroxides dissolve in alkali.
Statement $II$: Solubility of alkaline earth metal hydroxides in water increases down the group.
In the light of the above statements,choose the most appropriate answer from the options given below:

Discuss the diagonal relationship between beryllium and aluminum metals.

Which of the following chlorides is covalent and soluble in ether?

Given below are two statements:
Statement $I$: Both $CaCl_2 \cdot 6H_2O$ and $MgCl_2 \cdot 8H_2O$ undergo dehydration on heating.
Statement $II$: $BeO$ is amphoteric whereas the oxides of other elements in the same group are acidic.
In the light of the above statements,choose the correct answer from the options given below:

Among the following,which is water insoluble?