Question

An oxide which forms salts when it reacts both with the acid and base

Answer 1

Amphoteric acid reacts with both acid and base like ZnO

Answer 2

An atmospheric substance is one which reacts with both acid and base. when atmospheric metals react with dilute hydrochloric or sulphuric acids they produce hydrogen gas and the solution of the metal chloride or Sulphate salt, depending upon the acid used.