EXPLOSIVES What are explosives and how they work? How many types of explosives are ? Fuel-air bomb or father of all bombs What is a detonation? Presentation is made by Nick . S and George.CH

What are explosives and how they work? Explosives are chemicals and, like all chemicals, should be treated safely and with respect. Unlike other chemicals, most explosives detonate rather than burn. Explosives are categorized into two basic types, low explosives and high explosives. Low explosives tend to deflagrate, rather than detonate, which means that they burn at a slower rate and create less pressure than high explosives. Low explosives are often used as propellants to force a bullet out of a gun or send a rocket into space. A detonation is a very rapid chemical reaction using oxygen that is contained in the material rather than in the air. In a detonation, the chemical reaction releases gases that rapidly expand and give off energy as they become hot. Low Explosives For many years, black powder was the most common low explosive used throughout the world. But black powder, or gun powder as it was commonly called, produced a large amount of smoke and was dangerous to use. Today black powder is still used for pyrotechnics (fireworks), special effects, and other specialized work, but it has been replaced in commercial blasting by safer, more productive explosive materials. High Explosives High explosives create more pressure and burn more quickly, detonating almost instantaneously. The proper use of high explosives by today’s explosives engineer, produces minimal ground vibrations and air overpressure.

How many types of explosives are ? Bombs A Bomb is an explosive weapon. Bombs are usually used in warfare, although terrorists groups also use them. Bombs kill or injure people and destroy buildings, airplanes, ships, and other targets. Most bombs consist of a metal case filled with explosives or chemicals and a means of exploding or scattering the contents. Most bombs are large and dropped from airplanes, but some bombs are small enough to be carried by hand. Such bombs are often used by terrorists. In warfare, small bombs may be thrown as grenades or fired from artillery. Gunpowder Gunpowder burns rapidly to produce a high-pressure gas. The expansion of this gas inside a gun barrel caused the bullet to accelerate faster, so gunpowder is used as an propellant in a variety of ammunition. It’s also used in explosives for blasting operations, fireworks, and fuses. Dynamite Dynamite is an important industrial explosive used in blasting out dam sites, canal beds, mines, quarries, and the foundations of large buildings. It’s also used for demolition in warfare. The main explosive ingredient in dynamite is an oily liquid called nitroglycerin. Nitroglycerin Nitroglycerin, A.K.A. nitroglycerol, is a powerful explosive by itself, as well a being an ingredient in explosives like dynamite. Pure nitroglycerol is a heavy, oily, clear liquid. Commercial nitroglycerin is usually straw coloured.

Guncotton Guncotton is obtained when cotton or purified wool cellulose is soaked in a mix of sulphuric acids and nitric acids. The soaked cotton is drained from the acid mixture and then boiled in water to remove the impurities. Trinitrotoluene or more specifically, 2,4,6-trinitrotoluene, is a chemical compound with the formula C6H2(NO2)3CH3. This yellow-colored solid is sometimes used as a reagent in chemical synthesis, but it is best known as a useful explosive material with convenient handling properties. The explosive yield of TNT is considered to be the standard measure of strength of bombs and other explosives. In chemistry, TNT is used to generate charge transfer salts. Interesting is that It self energy of explosive Trinitrotoluene is insignificant. At explosion of 1 kg of Trinitrotoluene 6-8 times less energy is emitted, than at combustion of 1 kg of coal, but this energy at explosion is emitted in tens of millions times quicker, than at usual processes of burning. Besides, coal doesn't contain an oxidizer. Pyrotechnic substance (or a mix) — substance or a mix of substances which are intended for production of effect in the form of heat, fire, a sound or a smoke or their combination as a result of the self-sustaining exothermic chemical reactions proceeding without a detonation.

Amatol is a highly explosive material made from a mixture of TNT and ammonium nitrate. The British name originates from the words ammonium and toluene .Similar mixtures were known as Schneiderite in France. Amatol was used extensively during World War I and World War II, typically as an explosive in military weapons such as aircraft bombs, shells, depth charges and naval mines. It was eventually replaced with alternative explosives such as Composition B, torpex and tritonal. Because the proportion of TNT is significantly lower than in its military counterpart, ammonite has much less destructive power; given ammonite's use, this is not a problem. In general, a 30 kilogram charge of ammonite is roughly equivalent to 20 kilograms of TNT. RDX, an initialism for Research Department Explosive, is an explosive nitroamine widely used in military and industrial applications. It was developed as an explosive which was more powerful than TNT, and it saw wide use in WWII. RDX is also known as cyclonite, hexogen. Its chemical name is cyclotrimethylenetrinitramine; In its pure, synthesized state RDX is a white, crystalline solid. It is often used in mixtures with other explosives and plasticizers, phlegmatizers or desensitizers. RDX is stable in storage and is considered one of the most powerful and brisant of the military high explosives. RDX is widely used by terrorists

Fuel-air bomb or father of all bombs A thermobaric weapon, which includes the type known as a "fuel-air bomb", is an explosive weapon that produces a blast wave of a significantly longer duration than those produced by condensed explosives. This is useful in military applications where its longer duration increases the numbers of casualties and causes more damage to structures. There are many different variants of thermobaric weapons rounds that can be fitted to hand held launchers such as rocket-propelled grenades and anti-tank weapons. Thermobaric explosives rely on oxygen from the surrounding air, whereas most conventional explosives consist of a fuel-oxidizer premix (for instance, gunpowder contains 25% fuel and 75% oxidizer). Thus, on a weight-for-weight basis they are significantly more energetic than normal condensed explosives. Their reliance on atmospheric oxygen makes them unsuitable for use underwater, at high altitude or in adverse weather. However, they have significant advantages when deployed inside confined environments such as tunnels, caves, and bunkers.

Nuclear weapon Thermonuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission ("atomic") bomb test released the same amount of energy as approximately 20,000 tons of TNT. The first thermonuclear ("hydrogen") bomb test released the same amount of energy as approximately 10,000,000 tons of TNT. A modern thermonuclear weapon weighing little more than 2,400 pounds (1,100 kg) can produce an explosive force comparable to the detonation of more than 1.2 million tons (1.1 million tonnes) of TNT.] Thus, even a small nuclear device no larger than traditional bombs can devastate an entire city by blast, fire and radiation. Nuclear weapons are considered weapons of mass destruction, and their use and control have been a major focus of international relations policy since their debut. Thermonuclear weapon A thermonuclear weapon is a nuclear weapon design that uses the heat generated by a fission bomb to compress a nuclear fusion stage. This indirectly results in a greatly increased energy yield—explosive "power". It is colloquially referred to as a hydrogen bomb or H-bomb because it employs hydrogen fusion, though in most applications the majority of its destructive energy comes from uranium fission, not hydrogen fusion by itself. The fusion stage in such weapons is required to efficiently cause the large quantities of fission characteristic of most thermonuclear weapons.

THE END OR KAAABOOOM http://en.wikipedia.org/wiki/Amatol#Ammonite http://www.megabook.ru/Rubricator.asp?RNode=4062 http://www.howstuffworks.com/nuclear-bomb.htm http://www.infoplease.com/encyclopedia/history/hydrogen-bomb.html http://www.fas.org/man/dod-101/sys/dumb/fae.htm and many others