Which particles are involved in the reduction reaction at the cathode?

In a reduction reaction at the cathode, electrons are the primary particles involved. Reduction is defined as the gain of electrons by a chemical species, which leads to a decrease in its oxidation state. At the cathode, electrical energy drives the flow of electrons from an external circuit into the cathodic area, where these electrons participate in reduction reactions, typically allowing other species, like ions or molecules in solution, to gain electrons and become reduced.

To visualize this process, consider a galvanic cell or an electrolytic cell. In these systems, the cathode is the electrode where reduction occurs because it attracts positively charged ions from the solution, which then utilize the incoming electrons to complete their reduction.

This fundamental concept is crucial in understanding electrochemical reactions and is a key component in topics like corrosion science, battery operation, and other electrochemical processes.