i) Alkali metals and alkaline earth metals can form alkali with water.
ii) By precipitation with NaOH, insoluble metal hydroxide are prepared.
-Alkali earth metal hydroxides are sparingly soluble
-Other are insoluble
-Alkali metal hydroxides are thermally stable except (thermally unstable).
-Rest other are thermally unstable i.e. decompose on heating.
-Similar to that of respective oxides.