(c) amphoteric
Oxides of aluminium and zinc react with both acids and bases to produce salt and water. Such oxides are called amphoteric oxides.
Source: Chapter 3, Section 3.2.1
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The key term here is amphoteric — meaning the oxide behaves as both acidic and basic. The textbook explicitly states: "aluminium oxide and zinc oxide show the properties of both basic as well as acidic oxides — these are known as amphoteric oxides." Students must not confuse amphoteric with basic (most metal oxides are basic, but Al₂O₃ and ZnO are exceptions). Remembering Al and Zn as the two standard examples of amphoteric oxides is essential for MCQs and short-answer questions.