1. The problem statement, all variables and given/known data The fluoride which is most soluble in water is: a)CaF2 b)BaF2 c)SrF2 d)BeF2 2. Relevant equations none 3. The attempt at a solution the answer given is D. but BeF2 is covalent in nature and is soluble in organic solvents. Due to more electropositivity of Ba, BaF2 will have more ionic nature. On the other hand, since F is smaller compared to Ba, according to Fajan's rule, it can easily polarize Ba and it will have more covalent nature. So i am confused about option C.