What is reduction in the context of a chemical reaction?

Reduction refers to a specific type of reaction in which a substance gains electrons. This process often occurs in conjunction with oxidation, where a different substance loses electrons. Together, these processes are fundamental to redox (reduction-oxidation) reactions, which are prevalent in many chemical and biological systems.

When a substance gains electrons, its oxidation state decreases, which is a key indicator of reduction. Electrons themselves carry a negative charge, so when a substance gains electrons, it also becomes more negatively charged or less positive in charge, indicating a reduction in its oxidative state.

Understanding this principle is crucial for analyzing various chemical reactions and processes, including those found in electrochemistry, combustion, and metabolic pathways. Recognizing that reduction specifically involves the gain of electrons helps clarify broader topics such as electron transfer and the balancing of chemical equations.