HOW TO SEE THE RUSTING OF A METAL Materials : A rough steel string A thick plastic glass Three tablespoons of vinegar Steps : Place the string in the glass Pour the vinegar over the string Observe the color of the string immediately and after a period of two hours Pay attention to the color of the string, it is silver in the beginning, but some parts of it will become reddish brown What should you watch carefully after pouring the vinegar over the string?