What qualifies a material as explosible?

A material is qualified as explosible primarily based on its ability to undergo a rapid chemical change that results in the release of energy, specifically in the form of gas and heat. The correct answer pertains to a pressure ratio of 2.0 or greater obtained during explosibility testing, which indicates that the material can produce a significant amount of energy in a confined space, leading to an explosive reaction.

This testing measures the ability of a substance to create a dangerous pressure wave upon ignition, which is essential for classifying it as explosible. When a material reaches a pressure ratio of 2.0 or higher, it demonstrates a capacity for potential explosion under specific conditions, indicating that it can transition from a stable state to an unstable one that causes an explosive event.

The other options describe characteristics related to flammability or thermal properties but do not specifically define explosibility in the context of pressure and rapid energy release necessary for an explosion. Thus, while they pertain to chemical behavior and energy release, they lack the focus on the explosive potential that is clearly outlined through the pressure ratio in designated testing conditions.