Which of the following is the weakest base among $NaOH$,$Ca(OH)_2$,$KOH$,and $Ba(OH)_2$?

Which of the following magnetic properties is exhibited by the compounds of alkaline earth metals?

The reason for adding gypsum to the clinker during the production of cement is .........

$(a)$ Give reactivity of alkaline earth metals towards air,water,dihydrogen and acids.
$(b)$ Explain reducing nature of alkaline earth metals.
$(c)$ Give chemical reaction of alkaline earth metals with liquid ammonia.

The compound$(s)$ of alkaline earth metals,which are amphoteric in nature is/are

Observe the following compounds.
$(i)$ $CaCO_3$
$(ii)$ $MgSO_4$
$(iii)$ $BaCl_2$
$(iv)$ $Sr(NO_3)_2$
$(v)$ $MgBr_2$
$(vi)$ $MgCl_2$
The oxoacid salts of group $II$ elements from the above list are