In this section, we investigate the chemical effects of electric current, focusing on how different liquids can either conduct electricity or not. We learn that many liquids, especially solutions of acids, bases, and salts, are good conductors of electricity. Through practicality and experimentation, such as testing lemon juice and vinegar with a circuit tester, we observe that while some liquids allow the passage of electric current, others do not. Experiments demonstrate that the presence of ions, typically from dissolved substances, allows for electrical conduction.
Moreover, the section explores how an electric current can precipitate chemical reactions through electrolysis—producing gas bubbles and changing the properties of solutions. This leads us to the topic of electroplating, where a layer of one metal is deposited onto another through the process of applying current to a solution containing metal ions. Thus, electroplating has practical applications in various fields, making ordinary metal objects shiny or corrosion-resistant with metal coatings. Throughout, a series of activities and hypothetical questions lay the groundwork for understanding the principles governing these chemical effects.