Match Column $(A)$ with the appropriate options in Column $(B)$.

Column $(A)$	Column $(B)$
$(a)$ $BeO$	$(p)$ Amphoteric
$(b)$ $MgCO_3 \cdot CaCO_3$	$(q)$ Dolomite
$(c)$ $BeCl_2$	$(r)$ Covalent
$(d)$ $Al(OH)_3$	$(s)$ Basic

$Be$ and $Al$ exhibit many properties which are similar,but the two elements differ in:

Choose the correct statements from the following:
$(I)$ In vapour phase $BeCl_2$ exists as a chlorobridged dimer.
$(II)$ $BeSO_4$ is readily soluble in water.
$(III)$ $BeO$ is completely basic in nature.
$(IV)$ $BeCO_3$ being unstable,is kept in an atmosphere of $CO_2$.
$(V)$ $BeCO_3$ is the least soluble among all the carbonates of group $2$ elements.

The setting of Plaster of Paris is:

Which of the following properties of the alkaline earth metals increase from $Be$ to $Ba$?
$(i)$ Atomic radius
$(ii)$ Ionisation energy
$(iii)$ Nuclear charge

Write a note on halides of alkaline earth metal elements.