Which statement regarding the persistency and volatility of chemical agents is accurate?

Regarding the persistency and volatility of chemical agents, the statement that VX is a highly persistent nerve agent is accurate. VX is known for its stability in various environmental conditions, allowing it to remain effective for extended periods. This high level of persistence means that VX can contaminate areas for days or even weeks, posing a significant hazard to individuals who come into contact with it.

In contrast, chlorine is a gas that is quite volatile, meaning it can evaporate and disperse quickly in the air, which reduces its duration of harmful effects in a localized area. Mustard gas, contrary to the assertion about its non-persistency, actually has a high level of persistence and can linger in the environment. Most chemical agents do not evaporate rapidly; instead, many are designed to have varying degrees of persistency based on their intended use in warfare or other contexts. Thus, VX's designation as a highly persistent nerve agent is the key aspect that makes this statement accurate.