Which of the following alkaline earth metals shows anomalous behavior and has an electronegativity similar to that of aluminum?

Highest melting point among the following is displayed by

The solubility of sulfates in water decreases down the group for $Be$ to $Ba$. The correct order is $BeSO_4 > MgSO_4 > CaSO_4 > SrSO_4 > BaSO_4$. The reason for this is:

Which one of the following statements is $NOT$ correct about the compounds of alkaline earth metals?

The correct sequence of thermal stability of the following carbonates is:

The fluoride which is most soluble in water is