What is photodecomposition?

Photodecomposition refers to the process whereby a substance undergoes a chemical breakdown as a result of exposure to light, particularly ultraviolet (UV) radiation. This phenomenon is significant in various fields such as environmental science and agricultural practices, where sunlight can affect the stability and degradation of organic materials, pollutants, and even certain plants' chemical compounds.

In photodecomposition, the light energy absorbed by a substance can disrupt chemical bonds, leading to the formation of new substances or the breakdown of the original material. This is particularly important in the context of landscape maintenance, as understanding how plant materials or fertilizers may degrade under sunlight can influence the timing and methods of application.

The other options describe different types of breakdown processes that are not light-related. For example, exposure to water leads to hydrolysis, heat can cause thermal degradation, and microbial activity results in biological decomposition. Each of these processes involves different mechanisms and environmental factors than photodecomposition, making it clear why the correct answer specifically identifies the role of light in chemical breakdown.