The article tells about when such a chemical element as uranium was discovered, and in which industries this substance is used today.
Uranium is a chemical element in the energy and military industry
At all times, people have tried to find highly efficient sources of energy, and ideally - to create a so-called perpetual motion machine. Unfortunately, the impossibility of its existence was theoretically proved and substantiated back in the 19th century, but scientists still never lost hope of realizing the dream of some kind of device that would be capable of producing a large amount of "clean" energy for a very long time.
Partly this was realized with the discovery of such a substance as uranium. A chemical element with this name formed the basis for the development of nuclear reactors, which in our time provide energy to entire cities, submarines, polar ships, and so on. True, their energy cannot be called “clean”, but in recent years many companies have been developing compact tritium-based “atomic batteries” for wide sale - they have no moving parts and are safe for he alth.
However, in this article we will analyze in detail the history of the discovery of a chemical elementcalled uranium and the reaction of fission of its nuclei.
Definition
Uranium is a chemical element that has atomic number 92 in the periodic table of Mendeleev. Its atomic mass is 238.029. It is designated by the symbol U. Under normal conditions, it is a dense, heavy silvery metal. If we talk about its radioactivity, then uranium itself is an element with weak radioactivity. It also does not contain completely stable isotopes. And the most stable of the existing isotopes is uranium-338.
We figured out what this element is, and now let's look at the history of its discovery.
History
Such a substance as natural uranium oxide has been known to people since ancient times, and ancient masters used it to make glaze, which was used to cover various ceramics for water resistance of vessels and other products, as well as their decorations.
The year 1789 was an important date in the history of the discovery of this chemical element. It was then that the chemist and German-born Martin Klaproth was able to obtain the first metallic uranium. And the new element got its name in honor of the planet discovered eight years earlier.
For almost 50 years, the uranium obtained then was considered a pure metal, however, in 1840, a chemist from France, Eugene-Melchior Peligot, was able to prove that the material obtained by Klaproth, despite suitable external signs, was not a metal at all, but uranium oxide. A little later, the same Peligo receivedreal uranium is a very heavy gray metal. It was then that the atomic weight of such a substance as uranium was first determined. The chemical element in 1874 was placed by Dmitri Mendeleev in his famous periodic table of elements, and Mendeleev doubled the atomic weight of the substance twice. And only 12 years later, it was experimentally proved that the great chemist was not mistaken in his calculations.
Radioactivity
But the really widespread interest in this element in the scientific community began in 1896, when Becquerel discovered the fact that uranium emits rays that were named after the researcher - Becquerel rays. Later, one of the most famous scientists in this field, Marie Curie, called this phenomenon radioactivity.
The next important date in the study of uranium is considered to be 1899: it was then that Rutherford discovered that the radiation of uranium is inhomogeneous and is divided into two types - alpha and beta rays. And a year later, Paul Villar (Villard) discovered the third, the last type of radioactive radiation known to us today - the so-called gamma rays.
Seven years later, in 1906, Rutherford, on the basis of his theory of radioactivity, conducted the first experiments, the purpose of which was to determine the age of various minerals. These studies laid the foundation, among other things, for the formation of the theory and practice of radiocarbon analysis.
Fission of uranium nuclei
But, perhaps, the most important discovery, thanks to which thewidespread mining and enrichment of uranium for both peaceful and military purposes is the process of fission of uranium nuclei. It happened in 1938, the discovery was carried out by the German physicists Otto Hahn and Fritz Strassmann. Later, this theory received scientific confirmation in the works of several more German physicists.
The essence of the mechanism they discovered was as follows: if you irradiate the nucleus of the uranium-235 isotope with a neutron, then, capturing a free neutron, it begins to divide. And, as we all now know, this process is accompanied by the release of an enormous amount of energy. This happens mainly due to the kinetic energy of the radiation itself and the fragments of the nucleus. So now we know how uranium fission happens.
The discovery of this mechanism and its results is the starting point for the use of uranium for both peaceful and military purposes.
If we talk about its use for military purposes, then for the first time the theory that it is possible to create conditions for such a process as a continuous fission reaction of the uranium nucleus (since huge energy is needed to detonate a nuclear bomb) was proved by Soviet physicists Zeldovich and Khariton. But in order to create such a reaction, uranium must be enriched, since in its normal state it does not have the necessary properties.
We got acquainted with the history of this element, now we will figure out where it is used.
Uranium isotope uses and types
After the discovery of such a process as the chain fission reaction of uranium, physicists were faced with the question of where to use it?
Currently, there are two main areas where uranium isotopes are used. This is a peaceful (or energy) industry and military. Both the first and the second use the nuclear fission reaction of the uranium-235 isotope, only the output power differs. Simply put, in a nuclear reactor, there is no need to create and maintain this process with the same power that is necessary to carry out the explosion of a nuclear bomb.
So, the main industries in which the uranium fission reaction is used were listed.
But obtaining the uranium-235 isotope is an extremely complex and costly technological task, and not every state can afford to build enrichment plants. For example, to obtain twenty tons of uranium fuel, in which the content of the uranium 235 isotope will be from 3-5%, it will be necessary to enrich more than 153 tons of natural, "raw" uranium.
The uranium-238 isotope is mainly used in the design of nuclear weapons to increase their power. Also, when it captures a neutron, followed by a beta decay process, this isotope can eventually turn into plutonium-239 - a common fuel for most modern nuclear reactors.
Despite all the shortcomings of such reactors (high cost, complexity of maintenance, danger of an accident), their operation pays off very quickly, and they produce incomparably more energy than classical thermal or hydroelectric power plants.
Also, the reaction of fission of the uranium nucleus made it possible to create nuclear weapons of mass destruction. It is distinguished by its enormous strength, relativecompactness and the fact that it is capable of making large areas of land unsuitable for human habitation. True, modern atomic weapons use plutonium, not uranium.
Depleted uranium
There is also such a variety of uranium as depleted. It has a very low level of radioactivity, which means it is not dangerous to humans. It is used again in the military sphere, for example, it is added to the armor of the American Abrams tank to give it additional strength. In addition, in almost all high-tech armies you can find various shells with depleted uranium. In addition to their high mass, they have another very interesting property - after the destruction of the projectile, its fragments and metal dust ignite spontaneously. And by the way, for the first time such a projectile was used during the Second World War. As we can see, uranium is an element that has been used in various fields of human activity.
Conclusion
According to scientists' forecasts, around 2030, all large uranium deposits will be completely depleted, after which the development of its hard-to-reach layers will begin and the price will rise. By the way, uranium ore itself is absolutely harmless to people - some miners have been working on its extraction for generations. Now we have figured out the history of the discovery of this chemical element and how the fission reaction of its nuclei is used.
By the way, an interesting fact is known - uranium compounds have long been used as paints for porcelain andglass (so-called uranium glass) until the 1950s.
