Answer: The oxides of hard metal or the transition metals oxides like oxides of copper, zinc, iron, and chromium do not dissolve in water due to their limited basicity. Alkaline earth metal oxides also form hydroxides in water but these hydroxides themselves give slaked solutions and are not completely soluble.
Explanation: The oxides of hard metal or the transition metals oxides like oxides of copper, zinc, iron, and chromium do not dissolve in water due to their limited basicity. Alkaline earth metal oxides also form hydroxides in water but these hydroxides themselves give slaked solutions and are not completely soluble.