An explosive material, also called an explosive, is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure.
An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases.
In physics, sound is a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a medium such as air or water.
In physics, heat is energy that spontaneously passes between a system and its surroundings in some way other than through work or the transfer of matter.
An explosive charge is a measured quantity of explosive material, which may be composed of a single ingredient or a combination of two or more.
The potential energy stored in an explosive material may, for example, be
chemical energy, such as nitroglycerin or grain dust
Nitroglycerin, also known as nitroglycerine, trinitroglycerin, trinitroglycerine, nitro, glyceryl trinitrate, or 1,2,3-trinitroxypropane, is a heavy, colorless, oily, explosive liquid most commonly produced by nitrating glycerol with white fuming nitric acid under conditions appropriate to the formation of the nitric acid ester.
In the grain trade, a grain elevator is a tower containing a bucket elevator or a pneumatic conveyor, which scoops up grain from a lower level and deposits it in a silo or other storage facility.
In chemistry, chemical energy is the potential of a chemical substance to undergo a transformation through a chemical reaction to transform other chemical substances.
pressurized gas, such as a gas cylinder or aerosol can
Aerosol spray is a type of dispensing system which creates an aerosol mist of liquid particles.
A gas cylinder or tank is a pressure vessel used to store gases at above atmospheric pressure.
nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239
In nuclear engineering, fissile material is material capable of sustaining a nuclear fission chain reaction.
Isotopes are variants of a particular chemical element which differ in neutron number.
Uranium-235 is an isotope of uranium making up about 0.72% of natural uranium.
Explosive materials may be categorized by the speed at which they expand.
Materials that detonate are said to be "high explosives" and materials that deflagrate are said to be "low explosives".
Detonation is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it.
Explosives may also be categorized by their sensitivity.
Sensitive materials that can be initiated by a relatively small amount of heat or pressure are primary explosives and materials that are relatively insensitive are secondary or tertiary explosives.
A wide variety of chemicals can explode; a smaller number are manufactured specifically for the purpose of being used as explosives.
The remainder are too dangerous, sensitive, toxic, expensive, unstable, or prone to decomposition or degradation over short time spans.
In contrast, some materials are merely combustible or flammable if they burn without exploding.
A burn is a type of injury to skin, or other tissues, caused by heat, cold, electricity, chemicals, friction, or radiation.
Combustibility is a measure of how easily a substance will set on fire, through fire or combustion.
The distinction, however, is not razor-sharp.
Certain materials—dusts, powders, gasses, or volatile organic liquids—may be simply combustible or flammable under ordinary conditions, but become explosive in specific situations or forms, such as dispersed airborne clouds, or confinement or sudden release.
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a constant volume independent of pressure.