What term refers to the breakdown of chemicals due to sunlight?

The term that refers to the breakdown of chemicals due to sunlight is photodegradation. This process involves the absorption of light, particularly ultraviolet (UV) radiation, which leads to the breaking of chemical bonds within the molecules of the substance. As a result, photodegradation can significantly affect the stability and effectiveness of pesticides and other chemicals when exposed to sunlight, ultimately influencing their environmental impact and degradation rates.

In contrast, oxidation refers to a chemical reaction involving the loss of electrons, often resulting in the formation of free radicals or other reactive species. Biodegradation involves the breakdown of substances by biological organisms, primarily microorganisms, while thermal degradation involves the decomposition of materials due to exposure to high temperatures. Each of these terms describes different mechanisms of degradation with distinct processes and environmental implications.