One of the most important metals for metallurgy is manganese. In addition, it is generally a rather unusual element with which interesting facts are associated. Important for living organisms, needed in the production of many alloys, chemicals. Manganese is a chemical element, a photo of which can be seen below. It is its properties and characteristics that we will consider in this article.
Characteristic of a chemical element
If we talk about manganese as an element of the periodic system, then first of all we should characterize its position in it.
- Located in the fourth major period, the seventh group, secondary subgroup.
- Ordinal number - 25. Manganese is a chemical element, the charge of the nuclei of atoms of which is +25. The number of electrons is the same, neutrons - 30.
- The value of the atomic mass is 54, 938.
- Designation of the chemical element manganese - Mn.
- Latin name - manganese.
Situated between chromium and iron, which explains its similarity with them in physical and chemical characteristics.
Manganese - chemical element: transition metal
If we consider the electronic configuration of a reduced atom, then its formula will look like: 1s22s22p6 3s23p64s23d5. It becomes obvious that the element we are considering is a transition metal from the d-family. Five electrons on the 3d sublevel indicate the stability of the atom, which is manifested in its chemical properties.
As a metal, manganese is a reducing agent, but most of its compounds are capable of exhibiting fairly strong oxidizing abilities. This is due to the different oxidation states and valences that this element has. This is the peculiarity of all metals of this family.
Thus, manganese is a chemical element that is located among other atoms and has its own special characteristics. Let's consider what these properties are in more detail.
Manganese is a chemical element. Oxidation state
We have already given the electronic formula of the atom. According to her, this element is able to exhibit several positive oxidation states. This is:
- 0;
- +2;
- +3;
- +4;
- +6;
- +7.
The valency of an atom is IV. The most stable are those compounds in which manganese has the values +2, +4, +6. The highest degree of oxidation allows compounds to act as the strongest oxidizing agents. For example: KMnO4, Mn2O7.
Compounds with +2 are reducing agents, manganese (II) hydroxide has amphoteric properties, with a predominance of basic ones. Intermediate oxidation states form amphoteric compounds.
Discovery history
Manganese is a chemical element that was not discovered immediately, but gradually and by different scientists. However, its compounds have been used by people since ancient times. Manganese (IV) oxide was used for glass smelting. One Italian stated the fact that the addition of this compound in the chemical production of glasses turns their color purple. Along with this, the same substance helps to eliminate haze in colored glasses.
Later in Austria, the scientist Kaim managed to obtain a piece of metallic manganese by exposing pyrolysite (manganese (IV) oxide), potash and coal to high temperatures. However, this sample had many impurities, which he could not eliminate, so the discovery did not take place.
Even later, another scientist also synthesized a mixture in which a significant proportion was pure metal. It was Bergman, who had previously discovered the element nickel. However, he was not destined to finish the job.
Manganese is a chemical element, which was first obtained and isolated as a simple substance by Karl Scheele in 1774. However, he did this together with I. Gan, who completed the process of smelting a piece of metal. But even they failed to completely rid it of impurities and get a 100% product yield.
Nevertheless, this time has becomethe discovery of this atom. The same scientists attempted to give a name as the discoverers. They chose the term manganesium. However, after the discovery of magnesium, confusion began, and the name of manganese was changed to the modern one (H. David, 1908).
Since manganese is a chemical element whose properties are very valuable for many metallurgical processes, over time it became necessary to find a way to obtain it in the purest form. This problem was solved by scientists all over the world, but was only able to be resolved in 1919 thanks to the work of R. Agladze, a Soviet chemist. It was he who found a method by which it is possible to obtain pure metal with a substance content of 99.98% from sulfates and chlorides of manganese by electrolysis. Now this method is applied all over the world.
Being in nature
Manganese is a chemical element, a photo of a simple substance of which can be seen below. In nature, there are many isotopes of this atom, the number of neutrons in which varies greatly. Thus, the mass numbers range from 44 to 69. However, the only stable isotope is the element with the value 55Mn, all the rest have either a negligibly short half-life or exist in too small quantities.
Since manganese is a chemical element whose oxidation state is very different, it also forms a lot of compounds in nature. In its pure form, this element does not occur at all. In minerals and ores, its constant neighbor is iron. In total, several of the most important rocks, which include manganese, can be identified.
- Pyrolusite. Compound formula: MnO2nH2O.
- Psilomelane, MnO2mMnOnH2O molecule.
- Manganite, formula MnOOH.
- Brownite is rarer than the rest. Formula Mn2O3.
- Gausmanite, formula MnMn2O4.
- Rhodonite Mn2(SiO3)2.
- Carbonate ores of manganese.
- Raspberry spar or rhodochrosite - MnCO3.
- Purpurite - Mn3PO4.
Besides this, you can designate a few more minerals, which also include the element in question. This is:
- calcite;
- siderite;
- clay minerals;
- chalcedony;
- opal;
- sand-silty compounds.
In addition to rocks and sedimentary rocks, minerals, manganese is a chemical element that is part of the following objects:
- Plant organisms. The largest accumulators of this element are: water chestnut, duckweed, diatoms.
- Rust mushrooms.
- Some types of bacteria.
- Following animals: red ants, crustaceans, molluscs.
- People - the daily requirement is approximately 3-5 mg.
- The waters of the oceans contain 0.3% of this element.
- Total content in the earth's crust 0.1% by mass.
In general, it is the 14th most abundant element of all on our planet. Among heavy metals, it is the second afteriron.
Physical properties
From the point of view of the properties of manganese, as a simple substance, several basic physical characteristics can be distinguished for it.
- In the form of a simple substance, it is a fairly solid metal (on the Mohs scale, the indicator is 4). Color - silvery-white, covered with a protective oxide film in the air, shiny in the cut.
- The melting point is 12460C.
- Boil - 20610C.
- Conductor properties are good, is paramagnetic.
- Metal density is 7.44 g/cm3.
- Exists in the form of four polymorphic modifications (α, β, γ, σ), differing in the structure and shape of the crystal lattice and the packing density of atoms. Their melting point is also different.
There are three main forms of manganese used in metallurgy: β, γ, σ. Alpha is rarer, as it is too fragile in its properties.
Chemical properties
From the point of view of chemistry, manganese is a chemical element whose ion charge varies greatly from +2 to +7. This leaves its mark on his activity. In free form in air, manganese reacts very weakly with water and dissolves in dilute acids. However, as soon as the temperature is increased, the activity of the metal increases dramatically.
So, he is able to interact with:
- nitrogen;
- carbon;
- halogens;
- silicon;
- phosphorus;
- sulfur and other nonmetals.
When heated without air, the metal easily passes into a vapor state. Depending on the oxidation state that manganese exhibits, its compounds can be both reducing agents and oxidizing agents. Some exhibit amphoteric properties. So, the main ones are characteristic of compounds in which it is +2. Amphoteric - +4, and acidic and strong oxidizing in the highest value +7.
Despite the fact that manganese is a transition metal, complex compounds for it are few. This is due to the stable electronic configuration of the atom, because its 3d sublevel contains 5 electrons.
Methods of obtaining
There are three main ways in which manganese (a chemical element) is obtained in industry. As the name is read in Latin, we have already designated - manganum. If you translate it into Russian, then it will be "yes, I really clarify, I discolor." Manganese owes its name to the manifest properties known since antiquity.
However, despite the fame, they managed to get it in its pure form for use only in 1919. This is done by the following methods.
- Electrolysis, product yield is 99.98%. In this way, manganese is obtained in the chemical industry.
- Silicothermal, or silicon reduction. With this method, silicon and manganese (IV) oxide are fused, resulting in the formation of a pure metal. The yield is about 68%, as a side effect is the combination of manganese with silicon to form silicide. Thethe method is used in the metallurgical industry.
- Aluminothermic method - restoration with aluminum. Also does not give too high product yield, manganese is formed contaminated with impurities.
The production of this metal is essential for many processes carried out in metallurgy. Even a small addition of manganese can greatly affect the properties of alloys. It has been proven that many metals dissolve in it, filling its crystal lattice.
In terms of extraction and production of this element, Russia ranks first in the world. This process is also carried out in countries such as:
- China.
- South Africa.
- Kazakhstan.
- Georgia.
- Ukraine.
Industrial use
Manganese is a chemical element, the use of which is important not only in metallurgy. but also in other areas. In addition to the metal in its pure form, various compounds of this atom are also of great importance. Let's designate the main ones.
- There are several types of alloys that, thanks to manganese, have unique properties. So, for example, Hadfield steel is so strong and wear-resistant that it is used for smelting parts for excavators, stone processing machines, crushers, ball mills, and armored parts.
- Manganese dioxide is an obligatory oxidizing element of electroplating, it is used to create depolarizers.
- Manganese compounds are needed for the implementation of organicsyntheses of various substances.
- Potassium permanganate (or potassium permanganate) is used in medicine as a strong disinfectant.
- This element is part of bronze, brass, forms its own alloy with copper, which is used to make aircraft turbines, blades and other parts.
Biological role
The daily requirement for manganese for a person is 3-5 mg. Deficiency of this element leads to depression of the nervous system, sleep disturbance and anxiety, dizziness. Its role has not yet been fully studied, but it is clear that, first of all, it has an impact on:
- growth;
- activity of the gonads;
- hormone work;
- blood formation.
This element is present in all plants, animals, humans, which proves its important biological role.
Interesting item details
Manganese is a chemical element, interesting facts about which can impress any person, as well as make you understand how important it is. Here are the most basic of them, which have found their mark in the history of this metal.
- During the difficult times of the civil war in the USSR, one of the first export products was ore containing a large amount of manganese.
- If manganese dioxide is fused with potassium hydroxide and s altpeter, and then the product is dissolved in water, amazing transformations will begin. The solution will first turn green, then the color will change to blue.after - purple. Finally, it will turn crimson and a brown precipitate will gradually fall out. If the mixture is shaken, then the green color will be restored again and everything will happen again. It is for this that potassium permanganate got its name, which translates as "mineral chameleon".
- If fertilizers containing manganese are applied to the ground, then the productivity of plants will increase and the rate of photosynthesis will increase. Winter wheat will form grains better.
- The largest block of the manganese mineral rhodonite weighed 47 tons and was found in the Urals.
- There is a ternary alloy called manganin. It consists of elements such as copper, manganese and nickel. Its uniqueness is that it has a high electrical resistance, which is independent of temperature, but is influenced by pressure.
Of course, that's not all there is to say about this metal. Manganese is a chemical element, interesting facts about which are quite diverse. Especially if we talk about the properties that he gives to various alloys.
