The oxide that is amphoteric is AI2O3, also known as aluminum oxide. An amphoteric oxide is one that can react with both acids and bases to form a salt and water. In other words, it can act as both an acid and a base. When aluminum oxide reacts with an acid, it behaves as a base and undergoes a neutralization reaction, such as: AI2O3 + 6HCl → 2AlCl3 + 3H2O On the other hand, when aluminum oxide reacts with a base, it behaves as an acid and undergoes an acid-base reaction, such as: AI2O3 + 2NaOH + 3H2O → 2NaAl(OH)4 The other oxides listed do not exhibit amphoteric behavior. Sodium oxide (Na2O), calcium oxide (CaO), and copper oxide (CuO) are basic oxides and will react with acids but not bases. Iron oxide (Fe2O3) is a basic oxide, but it is not soluble in water and therefore does not react with acids or bases.