Under air conditions, only aluminum and in particular iron, metal passivation
Iron and aluminum can be quickly dissolved in dilute HNO3 or dilute H2SO4, but the dissolution phenomenon in concentrated HNO3 or concentrated H2SO4 is almost completely stopped, carbon steel is usually easy to rust, if the appropriate amount of Ni and Cr is added to the steel, it becomes stainless steel. A phenomenon in which the chemical stability of metals or alloys is significantly enhanced by some factors is called passivation. The phenomenon of metal passivation caused by certain passivating agents (chemicals) is called chemical passivation. Such as concentrated HNO3, concentrated H2SO4, HClO3, K2Cr2O7, KMnO4 and other oxidants can passivate metals.
Magnesium is indeed able to form a protective film, this protective film is generated by the reaction with oxygen in the air, is a layer of oxide film. The principle of this layer of oxide film is the same as that of the protective film of aluminum, except that the metal is no longer in contact with oxygen to prevent rust, and it is not related to the reaction with dilute sulfuric acid.