A. B. C. D.
A.CaO>KCl>MgO>NaCl B.NaCl>KCl>RbCl>SrO C.MgO>RbCl>SrO>BaO D.MgO>NaCl>KCl>RbCl
A.SiO2 B.HF C.KF D.Pb