1. Nuclear fusion: modeled after the reaction that takes place in the sun, it uses tremendous amounts of heat to provide the fusing of lighter nuclei, often Deuterium (or H-2), to form a larger, heavier nucleus, which is, if Deuterium is used, often Hydrogen-4. However the heat used is tremendous, often up to 10,000,000 degrees Celcius. To provide this awesome heat, a small amount of nuclear fission is needed. These fusion explosives are called thermonuclear weapons, and are often compared to MILLIONS of tons of TNT exploding (megatons). Naturally, it does not release any
2. Nuclear fission: does not happen naturally, and is 1/800th the power of a nuclear fusion reaction. It involves the firing of a "neutron bullet" at an atom with an atomic number greater than 91, at which point it splits into two lighter elements, such as U-235 splitting into Krypton-92 and Barium-141, releasing an extra two neutrons, plus the one used to split it. These neutrons move with such speed as to split apart more nuclei. More than a million reactions can happen in a split second, this is called the nuclear chain reaction. These individual atoms release energy that is often compared, in weapons, to tens up to hundreds of thousands of tons of TNT. Nuclear reaction...
When the warhead is detinated, nuclear atoms are split causing nuclear fusion.
Here is the chemical formula according to nuclearweaponarchive.org:
D + T -> He-4 (3.5 MeV) + n (14.1 MeV)
The first nuclear bombs where used on August 6, 1945. The united states droped two cities of Hiroshima and Nagasaki.
Here is some information on the first 2 used nuclear bombs
A nuclear weapon of the "Fat Man" type, the plutonium implosion type detonated over Nagasaki. 60 inches in diameter and 128 inches long, the weapon weighed about 10,000 pounds and had a yield approximating 21,000 tons of high explosives (Copy from U.S. National Archives, RG 77-AEC)
A nuclear weapon of the "Little Boy" type, the uranium gun-type detonated over Hiroshima. It is 28 inches in diameter and 120 inches long. "Little Boy" weighed about 9,000 pounds and had a yield approximating 15,000 tons of high explosives. (Copy from U.S. National Archives, RG 77-AEC
There are some highly uneducated information on the production and use of nuclear weapons throughout the web, such as people being able to build a operational nuclear weapon in there garage, this is not true due to the exact to-the-point conditions and enviroment needed to produce a nuclear weapon. The neds are so precise that labs are made just for the purpose of making another lab cabable to produce a nuclear weapon. Another misconception ...