試題詳解

30. The elements X, Y and Z can be combined to form the compound XYZ₃; the sum of the atomic numbers of X, Y and Z is 26. Y and Z are in the same period. Which of the following assumptions is correct?
(A) XYZ₃ is a water-soluble acid and X and Y form the covalent compound XY.
(B) XYZ₃ is a salt, slightly soluble in water, and X and Z form the ionic compound XZ.
(C) XYZ₃ is a water-soluble salt, and Y and Z can form the ionic compound YZ.
(D) XYZ₃ is an jonic compound, and Y and Z can form ionic compound YZ₂.
(E) XYZ₃ is a water-soluble salt, and X and Z can form an acidic compound X₂Z.