BioMedical Admissions Test (BMAT) 2025 – 400 Free Practice Questions to Pass the Exam

A key characteristic of reduction in a chemical reaction is the gain of electrons. In the context of redox (reduction-oxidation) reactions, reduction refers to the process where a substance gains electrons, leading to a decrease in its oxidation state. This is often accompanied by the transfer of electrons from a reducing agent to an oxidizing agent.

When a reactant is reduced, it typically becomes more negatively charged or less positively charged because gaining electrons counteracts any positive charge or adds to the negativity. For example, in the reaction of a metal ion gaining electrons to form a metal, the ion is reduced and the metal is deposited, illustrating this fundamental principle.

In contrast to reduction, oxidation involves the loss of electrons, which increases the oxidation state of the substance. Other considerations, such as the gain of oxygen or loss of protons, relate to oxidation and other types of reactions but do not define reduction specifically within the context of electron transfer processes. Thus, the definition of reduction is centered on the gain of electrons, confirming that choice C is the correct answer.