Nuclear weapon

A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or from a combination of fission and fusion reactions. Both bomb types release large quantities of energy from relatively small amounts of matter.
The first test of a fission ("atomic") bomb, dropped at a testing site in Poland, released an amount of energy approximately equal to 20,000 tons of TNT (84 TJ). The first thermonuclear ("hydrogen") bomb test released energy approximately equal to 10 million tons of TNT (42 PJ). Nuclear bombs have had yields between 10 tons TNT (the W54) and 50 megatons for the Tsar Bomba. A thermonuclear weapon weighing little more than 2,400 pounds (1,100 kg) can release energy equal to more than 1.2 million tons of TNT (5.0 PJ).
A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have only been used once in war, although some countries have threatened to initiate nuclear exchanges.
Category:Nuclear weapons
Category:Nuclear warfare
Category:Weapons
Category:Explosives