Amphoteric substances can be identified by repeatedly removing hydrogen ions from an acid or by repeatedly adding hydrogen ions to a base. NO−2 is not amphoteric because it is not an acid–it has no more hydrogen ions, let alone more hydrogen ions than can be removed.

How do you know if it's amphoteric?

Amphoteric substances can be identified by repeatedly removing hydrogen ions from an acid or by repeatedly adding hydrogen ions to a base. NO−2 is not amphoteric because it is not an acid–it has no more hydrogen ions, let alone more hydrogen ions than can be removed.

What are amphoteric examples?

Examples of amphoteric substances include water, amino acids, proteins, and many metal oxides and hydroxides. Oxides and hydroxides of aluminum, antimony, arsenic, antimony, bismuth, beryllium, chromium, cobalt, copper, gallium, germanium, gold, iron, lead, silver, tellurium, tin, and zinc are amphoteric.