What is one factor that determines the persistence and degradability of a chemical like anhydrous ammonia?

The persistence and degradability of a chemical like anhydrous ammonia are influenced by several environmental factors, making the option of "all of the above" the most comprehensive and accurate choice.

Temperature plays a significant role in chemical reactions, including the breakdown of substances. Higher temperatures can speed up chemical processes, potentially leading to faster degradation of ammonia. Conversely, lower temperatures may slow these processes, thus affecting how long the ammonia remains in the environment.

Soil type is another critical factor. Different soils have various compositions and microbial communities, which can affect how effectively ammonia is broken down. For example, soils rich in organic matter may have more microbial activity, facilitating the degradation process.

pH levels also have a profound influence on the behavior of chemicals. Ammonia is affected by pH as it can exist in different forms depending on the acidity or alkalinity of the environment. This can impact its mobility and degradation rates in soil and water.

Since each of these factors can independently and collectively influence the fate of anhydrous ammonia in the environment, acknowledging all of them as contributing elements underscores the complexity of chemical persistence and degradability. Thus, the inclusion of all these factors leads to a more accurate understanding of ammonia's environmental impact.