The energy released from a nuclear explosion is enormous. She is capable of destroying entire cities in a few minutes. This monstrous energy is released as a result of a nuclear reaction.
The mechanism of a nuclear chain reaction
It is known from the physics course that the nucleons in the nucleus - protons and neutrons - are held together by strong interactions. It significantly exceeds the forces of the Coulomb repulsion, so the nucleus as a whole is stable. In the 20th century, the great scientist Albert Einstein discovered that the mass of individual nucleons is somewhat greater than their mass in a bound state (when they form a nucleus). Where does some of the mass go? It turns out that it transforms into the binding energy of nucleons and thanks to it nuclei, atoms and molecules can exist.
Most of the known nuclei are stable, but there are also radioactive ones. They emit energy continuously, as they are subject to radioactive decay. The nuclei of such chemical elements are unsafe for humans, but they do not emit energy capable of destroying entire cities.
Colossal energy appears as a result of a nuclear chain reaction. The isotope of uranium-235, as well as plutonium, are used as nuclear fuel in an atomic bomb. When one neutron enters the nucleus, it begins to divide. A neutron, being a particle without an electric charge, can easily penetrate into the structure of the nucleus, bypassing the action of the forces of electrostatic interaction. As a result, it will begin to stretch. The strong interaction between nucleons will begin to weaken, while the Coulomb forces will remain the same. The uranium-235 nucleus will split into two (rarely three) fragments. Two additional neutrons will appear, which can then enter into a similar reaction. Therefore, it is called chain: what causes the fission reaction (neutron) is its product.
As a result of a nuclear reaction, energy is released, which bound the nucleons in the mother nucleus of uranium-235 (binding energy). This reaction underlies the operation of nuclear reactors and the explosion of the atomic bomb. For its implementation, one condition must be met: the mass of the fuel must be subcritical. At the moment of combining plutonium with uranium-235, an explosion occurs.
After the collision of plutonium and uranium nuclei, a powerful shock wave is formed, affecting all living things within a radius of about 1 km. The fireball that appeared at the explosion site gradually expands to 150 meters. Its temperature drops to 8 thousand Kelvin when the shock wave travels far enough. The heated air carries radioactive dust over great distances. A nuclear explosion is accompanied by powerful electromagnetic radiation.