Explosive
Definition
A chemical or mixture that undergoes rapid exothermic decomposition releasing large volumes of gas and heat when triggered by heat, shock, friction or electric stimulus. The reaction produces a pressure shock wave.
- Reaction type
- Rapid exothermic decomposition
- Output
- Large volume of gas and heat, producing a shock wave
- Triggers
- Heat, shock, friction, or electric stimulus
- Field
- Explosives classification and definition
Common questions
What separates an explosive from a substance that merely burns rapidly?+
The decomposition rate. An explosive reaction propagates fast enough to generate a genuine pressure shock wave, while ordinary rapid burning, even a fierce one, releases energy too slowly to produce that shock front.
Are all explosives detonating, high explosives?+
No. Explosives split broadly into low explosives, which deflagrate and are used for propulsion, such as black powder, and high explosives, which detonate and produce a true supersonic shock wave, such as TNT. Both meet the general definition but behave very differently.
Related terms
- Brisance
- The shattering power of a detonating explosive, distinct from heave (bulk displacement). Measured by the Trauzl lead block test. High-brisance explosives (RDX,...
- Deflagration
- A subsonic combustion front propagating through an explosive by thermal conduction. Characteristic of low explosives such as black powder and smokeless powder;...
- Detonation
- A supersonic shock wave coupled to a chemical reaction front, propagating through a high explosive at velocities between approximately 4,500 and 9,100...
- Detonator
- A small initiating charge of primary explosive (lead azide, lead styphnate, mercury fulminate or DDNP) that converts an electrical, mechanical or pyrotechnic...
- Oxygen Balance
- A percentage expressing the surplus or deficit of oxygen in an explosive molecule relative to stoichiometric complete oxidation of carbon to CO2...
- Sensitivity
- How easily an explosive is set off by impact, friction, spark, heat or shock. Primary explosives are highly sensitive; secondary explosives need...
- Velocity of Detonation (VoD)
- The speed at which the detonation wave propagates through an explosive, measured in metres per second. RDX: approximately 8,750 m/s; TNT: approximately...