Explosives are classified as low or high explosives based on their __________.

• A. Temperature
• B. Density
• C. Detonation velocity
• D. Heat of formation

Answer: (C)

The key idea is how quickly the reaction front moves through the material when the explosive is activated. This speed, called the detonation velocity, is the defining factor that separates low from high explosives.

Detonation velocity is the rate at which the detonation wave travels through the explosive. High explosives generate a true detonation with a shock wave that moves through the material at very high speeds, causing an almost instantaneous energy release and a powerful blast. Low explosives, by contrast, do not form that rapid detonation front; they burn or deflagrate much more slowly, and their energy release is much less violent in comparison. Because the pace of this energy release directly influences the blast characteristics and handling hazards, detonation velocity is the standard criterion used to classify explosives as low or high.

Temperature, density, and heat of formation affect how an explosive behaves, but they aren’t the basis for this classification.