Acid-base properties of oxides and hydrides

This is apparent from the reactions with water, when basic and acidic solutions are formed, respectively  

In between these two oxides comes AI2O3, which has negligible solubility in pure water, but reveals amphoteric character by dissolving in both acids and bases  

A related trend is apparent in the reactions of the hydrides with water. At the beginning of the Periods, the Group I and Group II hydrides give hydrogen gas and basic solutions with water, for example 

These basic properties contrast with the acidity of the hydrides of Group VII elements for example 

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