What process involves the alteration of a chemical by adding oxygen to its molecular structure?

The process of oxidation involves the addition of oxygen to a chemical compound, which often results in a change in its molecular structure and properties. This can lead to various chemical transformations, such as the formation of oxides or changes in the oxidation state of the compound. Oxidation is key in many biological and chemical processes, including respiration and combustion.

Reduction, on the other hand, can be thought of as the opposite of oxidation, where electrons are gained and typically involves a decrease in oxidation state. Hydrolysis refers to the reaction of a compound with water, breaking it down into simpler molecules. Photosynthesis is a biological process where plants convert carbon dioxide and water into glucose and oxygen using sunlight, which is distinct from the direct chemical alteration involved in oxidation.

Thus, oxidation accurately describes the specific chemical alteration characterized by the addition of oxygen to a molecule.