Which ion is typically formed by alkaline earth metals?

Consider the following statements:
Statement-$I$: Both $BeSO_4$ and $MgSO_4$ are readily soluble in water.
Statement-$II$: Among the nitrates of alkaline earth metals,only $Be(NO_3)_2$ on strong heating gives its oxide,$NO_2$,and $O_2$.

Solubility of sulphates of group $2$ elements decreases down the group due to

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:

The difference in the number of water molecules in gypsum and plaster of Paris is:

Which one of the following alkaline earth metals does not form hydride when it is heated with hydrogen directly?