In the context of chemical reactions, the section investigates how certain metals respond when placed in solutions of metal salts, specifically focusing on displacement reactions. When a more reactive metal is introduced to a salt solution containing a less reactive metal, a reaction occurs where the less reactive metal is displaced. For example, when copper wire is placed in an iron(II) sulfate solution and an iron nail is submerged in a copper(II) sulfate solution, observable reactions occur that provide insights into the reactivity series of metals. This section not only highlights individual reactions but also conceptualizes the broader framework of metal reactivity, which aids in predicting the outcomes of various metal interactions. A balanced chemical equation can be written for the reactions observed, reinforcing the understanding of displacement reactions.