The article tells about when such a chemical element as uranium was discovered, and in which industries this substance is used in our time.
Uranium is a chemical element in the energy and military industries
At all times, people have tried to find highly efficient energy sources, and ideally, to create the so-called perpetual motion machine. Unfortunately, the impossibility of its existence was theoretically proved and justified back in the 19th century, but scientists still never lost hope of fulfilling the dream of a kind of device that would be able to produce a large amount of “clean” energy for a very long time.
In part, it was possible to realize with the discovery of a substance such as uranium. A chemical element with this name formed the basis for the development of nuclear reactors, which nowadays provide energy to entire cities, submarines, polar vessels and more. 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 health.
However, in this article we will analyze in detail the history of the discovery of a chemical element called uranium and the fission reaction of its nuclei.
Definition
Uranium is a chemical element that has atomic number 92 in the periodic table. Its atomic mass is 238.029. It is designated by the symbol U. Under normal conditions, it is a dense, heavy metal of silver color. If we talk about its radioactivity, then uranium itself is an element with weak radioactivity. Also, it does not have completely stable isotopes in its composition. And the most stable of the existing isotopes is considered to be uranium-338.
With what this element is, we figured out, and now consider the history of its discovery.
History
A substance such as natural uranium oxide is known to people from ancient times, and ancient masters used it to make a glaze, which was coated with various ceramics for waterproofing vessels and other products, as well as their decorations.
An important date in the history of the discovery of this chemical element was 1789. It was then that a chemist and German by birth Martin Klaprot was able to get the first metal-like 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 Melcior Peligo was able to prove that the material obtained by Klaprot, despite suitable external signs, was not metal at all, but uranium oxide. A little later, all the same Peligo received real uranium - a very heavy metal of gray color. It was then that the atomic weight of a substance such as uranium was first determined. The chemical element in 1874 was placed by Dmitry Mendeleev in his famous periodic system of elements, with 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 a truly widespread interest in this element in scientific circles 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 area, Maria 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 heterogeneous and is divided into two types - alpha and beta rays. A year later, Paul Villard (Villard) discovered the third, last known 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, including the formation of the theory and practice of radiocarbon analysis.
Uranium fission
But, probably, the most important discovery, due to which widespread mining and enrichment of uranium began, both for peaceful and military purposes, is the process of fission of uranium nuclei. This happened in 1938, the discovery was made by the forces of German physicists Otto Hahn and Fritz Strassmann. Later this theory received scientific confirmation in the work of several other German physicists.
The essence of the mechanism they discovered was as follows: if the nucleus of the uranium-235 isotope is irradiated 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 a colossal 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 the fission of uranium nuclei occurs.
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, 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 Zel'dovich and Khariton. But in order to create such a reaction, uranium must be enriched, since in its usual state it does not possess the necessary properties.
We got acquainted with the history of this element, now we will figure out where it is used.
Application and types of uranium isotopes
After the discovery of a process such as the chain fission reaction of uranium, the question arose for physicists, where can it be used?
Currently, there are two main areas where uranium isotopes are used. This is a peaceful (or energy) industry and the military. Both the first and second use the 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 needed to carry out a nuclear bomb explosion.
So, the main industries that use the uranium fission reaction were listed.
But obtaining the uranium-235 isotope is an unusually 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 isotope 235 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 its power. Also, when it captures a neutron with the subsequent 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 fission reaction of the uranium nucleus allowed the creation of nuclear weapons of mass destruction. It is distinguished by tremendous strength, relative compactness and the fact that it can make large areas of land unsuitable for people to live. True, modern atomic weapons use plutonium, not uranium.
Depleted uranium
There is such a variety of uranium as depleted. It has a very low level of radioactivity, which means it is not dangerous to people. 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, various depleted uranium shells can be found . In addition to their high mass, they have another very interesting property - after the destruction of the projectile, its fragments and metal dust self-ignite. And by the way, for the first time such a shell was used during the Second World War. As we see, uranium is an element that has been used in various fields of human activity.
Conclusion
According to scientists, around 2030 all major uranium deposits will be completely depleted, after which the development of hard-to-reach layers will begin and the price will rise. By the way, the 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 and glass (the so-called uranium glass) until the 1950s.