Wyoming Pesticide Applicator Certification Practice Test

Which process involves the breakdown of chemicals by the action of sunlight?

1. Chemical degradation

2. Photodegradation

3. Pesticide movement in water

4. Microbial action

The correct answer is: Photodegradation

Photodegradation is a type of environmental degradation caused by the reaction of sunlight with chemical substances. This process is specifically caused by the energy in sunlight breaking down the chemical bonds of the substance, resulting in a breakdown of the substance's structure. Therefore, options A, C, and D are incorrect as they involve different processes that do not involve the action of sunlight. Chemical degradation and pesticide movement in water may involve other factors such as pH levels or water movement, while microbial action involves the use of living organisms to break down chemical substances. Therefore, option B, photodegradation, is the most fitting answer as it specifically refers to the breakdown of chemicals by the action of sunlight.