In chemistry, what type of reaction is defined by the loss of electrons?

• A. Reduction reaction
• B. Oxidation reaction
• C. Hydrolysis reaction
• D. Decomposition reaction

Answer: (B)

The type of reaction defined by the loss of electrons is an oxidation reaction. In the context of redox (reduction-oxidation) reactions, oxidation specifically refers to the process where an atom, ion, or molecule loses electrons. This can result in an increase in oxidation state. The classic example of oxidation can be observed in the reaction of metals with oxygen, where the metal is oxidized as it loses electrons.

In contrast, a reduction reaction involves the gain of electrons, leading to a decrease in oxidation state. Hydrolysis reactions involve the breaking down of compounds by reaction with water, while decomposition reactions refer to the breakdown of a single compound into two or more products. Therefore, the key feature of an oxidation reaction is the loss of electrons, distinguishing it clearly from the other types of reactions listed.