Explosives

Explosives are substances that produce violent chemical or nuclear reactions. These reactions generate large amounts of **[|heat]** and gas in a fraction of a second. Shock waves produced by rapidly expanded gasses are responsible for much of the destruction seen following an explosion. The power of most chemical explosives comes from the reaction of **[|oxygen]** with other **[|atoms]** such as **[|nitrogen]** and **[|carbon]**. This split-second chemical reaction results in a small amount of material being transformed into a large amount heat and rapidly expanding gas. The heat released in an explosion can incinerate nearby objects. The expanding gas can smash large objects like boulders and buildings to pieces. Chemical explosives can be set off, or detonated, by heat, **[|electricity]**, physical shock, or another explosive. The power of nuclear explosives comes from **[|energy]** released when the nuclei of particular heavy atoms are split apart, or when the nuclei of certain **[|light]** elements are forced together. These nuclear processes, called fission and fusion, release thousands or even millions of times more energy than chemical explosions. A single nuclear explosive can destroy an entire city and rapidly kill thousands of its inhabitants with lethal **[|radiation]**, intense heat and blast effects.

Chemical explosives are used in peacetime and in wartime. In peacetime they are used to blast rock and stone for **[|mining]** and quarrying, project rockets into **[|space]**, and fireworks into the sky. In wartime, they project missiles carrying warheads toward enemy targets, propel bullets from guns, artillery shells from cannon, and provide the destructive **[|force]** in warheads, mines, artillery shells, torpedoes, bombs, and hand grenades. So far, nuclear explosives have been used only in war.

he first chemical explosive was gunpowder, or black powder, a mixture of charcoal, **[|sulfur]**, and **[|potassium nitrate]** (or saltpeter). The Chinese invented it approximately 1,000 years ago. For hundreds of years, gunpowder was used mainly to create fireworks. Remarkably, the Chinese did not use gunpowder as a [|Explosives]weapon of war until long after Europeans began using it to shoot stones and spear-like projectiles from tubes and, later, **[|metal]** balls from cannon and guns. Europeans probably learned about gunpowder from travelers from the Middle East. Clearly by the beginning in the thirteenth century gunpowder was used more often to make war than to make fireworks in the West. The English and the Germans manufactured gunpowder in the early 1300s. It remained the only explosive for 300 hundred years, until 1628, when another explosive called fulminating gold was discovered. Gunpowder changed the lives of both civilians and soldiers in every Western country that experienced its use. (Eastern nations like China and Japan rejected the widespread use of gunpowder in warfare until the nineteenth century.) Armies and navies who learned to use it first—the rebellious Czech Taborites fighting the Germans in 1420 and the English Navy fighting the Spanish in 1587, for example—scored influential early victories. These victories quickly forced their opponents to learn to use gunpowder as effectively. This changed the way wars were fought, and won, and so changed the relationship between peoples and their rulers. Royalty could no longer hide behind stone walls in castles. Gunpowder blasted the walls away and helped, in part, to end the loyalty and servitude of peasants to local lords and masters. Countries with national armies became more important than local rulers as war became more deadly, due in large part to the use of gunpowder. It was not until the seventeenth century that Europeans began using explosives in peacetime to loosen **[|rocks]** in mines and clear fields of boulders and trees.

Read more: [|Explosives - History] []