What process involves the addition of oxygen to a compound?

The process that involves the addition of oxygen to a compound is known as oxidation. During oxidation, a substance gains oxygen atoms or loses hydrogen atoms as part of a chemical reaction. This reaction is a key concept in redox (reduction-oxidation) chemistry, where oxidation refers specifically to the increase in oxidation state due to the addition of oxygen or the removal of electrons.

In many chemical processes, such as the metabolism of organic materials or the combustion of fuels, oxidation plays a crucial role. For example, when fuels burn in the presence of oxygen, they undergo oxidation, releasing energy in the process. Thus, by defining oxidation in terms of oxygen addition and electron loss, it becomes clear why this is the correct answer, as it highlights the fundamental nature of the oxidation process within chemistry.