Phosphorus is a fairly common chemical element on our planet. Its name translates as “luminiferous,” because in its pure form it shines brightly in the dark. This element was discovered by accident, by the alchemist Henning Brand, when he tried to extract gold from urine. So phosphorus became the first element that alchemists were able to get through their experiments.
Phosphorus Characterization
It is chemically very active, so in nature it can only be found in the form of minerals - compounds with other elements, of which there are 190 species. The most important compound is calcium phosphate (the mineral apatite). Now many varieties of apatites are known, the most common of which is fluorapatite. Of the various types of apatites, sedimentary rocks, phosphorites, are composed.
For living organisms, phosphorus is very important because it is part of both plant and animal protein in the form of various compounds.
In plants, this element is found mainly in seed proteins, and in animal organisms - in various proteins of blood, milk, brain and nervous tissue cells . A large amount of phosphorus is contained in the form of calcium phosphate in the bones of vertebrates.
Phosphorus exists in three allotropic modifications: white phosphorus, red and black. Let's take a closer look at them.
White phosphorus can be obtained by quickly cooling its vapors. Then a solid crystalline substance is formed, which in its pure form is absolutely colorless and transparent. White phosphorus intended for sale is usually painted a slightly yellowish color and is very similar in appearance to wax. In the cold, this substance becomes brittle, and at a temperature above 15 degrees it acquires softness and can be easily cut with a knife.
White phosphorus does not dissolve in water, but it lends itself well to organic solvents. In air, it oxidizes very quickly (begins to burn) and at the same time glows in the dark. Actually, ideas about the luminous substance and detective stories about the Baskervilles dog are associated with white phosphorus. It is a powerful poison that acts deadly even in small doses.
Red phosphorus is a dark red solid, which in its properties is very different from that described above. It oxidizes in air very slowly, does not glow in the dark, lights up only when heated, it is impossible to dissolve it in organic solvents, and it is not poisonous. With strong heating, in which there is no access of air, it, without melting, turns into steam, from which, upon cooling, white phosphorus is obtained. When both elements are burned, phosphorus oxide is formed, which proves the presence of the same element in their composition. In other words, they are formed by one element - phosphorus - and are its allotropic modifications.
Black phosphorus is obtained from white at 200 degrees Celsius under high pressure. It has a layered structure, metallic luster and looks like graphite. Of all the solid species of this substance, it is the least active.
Phosphorus
Modern phosphorus production is about a million tons per year. Major manufacturers: USA, Holland, Canada, Germany.
The main part of the extracted phosphorus is spent on obtaining thermal phosphoric acid, which is used in the production of fertilizers and phosphates. White phosphorus is used as a smoke generating and incendiary agent, including for tracer ammunition.
Red is used to make an incendiary surface of a matchbox, and in the production of incandescent lamps it acts as a getter.
Phosphorus has found its application in metallurgy. It is used as an additive to produce alloys, solders, soft magnetic and antifriction alloys.