In redox reactions, what does oxidation refer to?

Oxidation in redox reactions is defined as the loss of electrons by a substance. This process is fundamental to understanding how redox (reduction-oxidation) reactions work. When a species undergoes oxidation, it increases its oxidation state because electrons carry a negative charge; losing them results in a more positive oxidation state.

In many redox reactions, electrons are transferred between reactants, leading to changes in their oxidation states. For example, consider the oxidation of metallic iron to iron ions. The iron atom loses electrons, which demonstrates oxidation as it turns from a neutral atom into a positively charged ion.

Moreover, this concept pairs with reduction, where another substance gains the electrons that were lost during the oxidation process. Thus, oxidation and reduction always occur simultaneously in redox reactions, with one substance being oxidized (losing electrons) and another being reduced (gaining electrons).

Understanding this core concept is crucial for analyzing various chemical reactions, including biochemical processes, combustion, and corrosion. The clear definition of oxidation as the loss of electrons offers clarity in identifying how different species interact during these reactions.