Aluminium is a reactive metal but is still used for packing food articles. Give reason

Aluminium ($Al$) is highly reactive when it is exposed to air. It forms a layer of Aluminium oxide ($A{l}_2{O}_3$). The formed Aluminium oxide ($A{l}_2{O}_3$) is going to act as a protective layer which is formed on the Aluminium ($Al$) metal surface.

The chemical reaction of Aluminium with air is as follows.

$\underset{Aluminium}{4Al\left(s\right)}+\underset{Oxygen}{3O_2\left(g\right)}\to \underset{Aluminiumoxide}{2A{l}_2{O}_3\left(s\right)}$

So, it is used for packing food articles as it creates a strong protective coating of Aluminium oxide ($A{l}_2{O}_3$) when exposed to air, which prevents further oxidation.