What characteristic defines oxidation in terms of electron transfer?

Oxidation is defined by the loss of electrons. When a substance undergoes oxidation, it not only loses electrons but also increases its oxidation state. This process is key in many chemical reactions, particularly in redox (reduction-oxidation) reactions where one species is oxidized and another is reduced.

In contrast, gaining electrons corresponds to reduction, which is the opposite process of oxidation. Therefore, understanding oxidation as the loss of electrons is fundamental in both chemistry and related fields such as biochemistry, where redox reactions are crucial.

The other potential answers don't align with the defining characteristic of oxidation. A stable charge or neutral charge doesn't convey the dynamic nature of electrons being transferred during oxidation and reduction processes, making the concept of electron loss critically important for grasping the foundational principles of these chemical reactions.