Metals are one of the most convenient materials to process. They also have their own leaders. For example, the basic properties of aluminum have been known to people for a long time. They are so suitable for use in everyday life that this metal has become very popular. What are the properties of aluminum as a simple substance and as an atom, we will consider in this article.
The history of the discovery of aluminum
For a long time, man has known the compound of the metal in question - potassium alum. It was used as an agent capable of swelling and binding the components of the mixture together; this was also necessary in the dressing of leather products. The existence of pure aluminum oxide became known in the 18th century, in its second half. However, no pure substance was obtained.
Managed to isolate the metal from its chloride for the first time the scientist H. K. Oersted. It was he who processed s alt with potassium amalgam and isolated a gray powder from the mixture, which was aluminum in its pure form.
Then it became clear that the chemical properties of aluminum are manifested in its high activity, strong reducing ability. Therefore, no one else worked with him for a long time.
However, in 1854, the Frenchman Deville was able to obtain metal ingots by melt electrolysis. This method is still relevant today. Especially mass production of valuable material began in the 20th century, when the problems of obtaining a large amount of electricity at enterprises were solved.
Today, this metal is one of the most popular and used in construction and household industries.
General characteristics of the aluminum atom
If we characterize the element under consideration by its position in the periodic system, we can single out several points.
- Ordinal number - 13.
- Located in the third minor period, the third group, the main subgroup.
- Atomic mass - 26, 98.
- Number of valence electrons - 3.
- The outer layer configuration is expressed as 3s23p1.
- Element name is aluminum.
- Metal properties are strong.
- Has no isotopes in nature, exists only in one form, with a mass number of 27.
- The chemical symbol is AL, read as "aluminum" in formulas.
- The oxidation state is one, equal to +3.
The chemical properties of aluminum are fully confirmed by the electronic structure of its atom, because having a large atomic radius and low electron affinity, it is able to act as a strong reducing agent, like all active metals.
Aluminum as a simple substance: physical properties
If we talk about aluminum, how aboutsimple substance, it is a silvery-white shiny metal. In air, it quickly oxidizes and becomes covered with a dense oxide film. The same thing happens with the action of concentrated acids.
The presence of such a feature makes products made of this metal resistant to corrosion, which, of course, is very convenient for people. Therefore, it is aluminum that finds such wide application in construction. The properties of the substance are also interesting in that this metal is very light, while being strong and soft. The combination of such characteristics is not available to every substance.
There are several basic physical properties that are characteristic of aluminum.
- High degree of malleability and ductility. Light, strong and very thin foil is made from this metal, it is also rolled into a wire.
- Melting point - 660 0C.
- Boiling point - 2450 0C.
- Density - 2.7 g/cm3.
- Crystal lattice volume face-centered, metallic.
- Connection type - metal.
Physical and chemical properties of aluminum determine the areas of its application and use. If we talk about everyday aspects, then the characteristics already considered by us above play a big role. As a light, durable and anticorrosive metal, aluminum is used in aircraft and shipbuilding. Therefore, these properties are very important to know.
Chemical properties of aluminum
From the point of viewchemistry, the metal in question is a strong reducing agent that is capable of exhibiting high chemical activity, being a pure substance. The main thing is to eliminate the oxide film. In this case, the activity increases sharply.
The chemical properties of aluminum as a simple substance are determined by its ability to react with:
- acids;
- alkali;
- halogens;
- grey.
It does not interact with water under normal conditions. At the same time, from halogens, without heating, it reacts only with iodine. Other reactions require temperature.
It is possible to give examples illustrating the chemical properties of aluminum. Interaction reaction equations with:
- acids - AL + HCL=AlCL3 + H2;
-
alkalis - 2Al + 6H2O + 2NaOH=Na[Al(OH)4] + 3H 2;
- halogens - AL + Hal=ALHal3;
- grey - 2AL + 3S=AL2S3.
In general, the most important property of the substance in question is its high ability to restore other elements from their compounds.
Restorative capacity
The reducing properties of aluminum are well traced in the reactions of interaction with oxides of other metals. It easily extracts them from the composition of the substance and allows them to exist in a simple form. For example: Cr2O3 + AL=AL2O3+ Cr.
In metallurgy, there is a whole technique for obtaining substances,based on such responses. It is called aluminothermy. Therefore, in the chemical industry, this element is used precisely to obtain other metals.
Spread in nature
In terms of prevalence among other metal elements, aluminum ranks first. Its content in the earth's crust is 8.8%. If compared with non-metals, then its place will be third, after oxygen and silicon.
Due to its high chemical activity, it is not found in its pure form, but only as part of various compounds. So, for example, there are many ores, minerals, rocks, which include aluminum. However, it is mined only from bauxites, the content of which is not too high in nature.
The most common substances containing the metal in question:
- feldspars;
- bauxites;
- granites;
- silica;
- aluminosilicates;
- bas alts and others.
In a small amount, aluminum is necessarily part of the cells of living organisms. Some species of club mosses and marine life are able to accumulate this element inside their bodies during their lives.
Receive
The physical and chemical properties of aluminum make it possible to obtain it in only one way: by electrolysis of a melt of the corresponding oxide. However, this process is technologically complex. The melting point of AL2O3 is over 2000 0C. Because of this, it cannot be electrolyzed directly. Soproceed as follows.
- Bauxites are mined.
- Clean them of impurities, leaving only aluminum oxide.
- Then the cryolite is melted.
- Add oxide there.
- This mixture is electrolyzed and pure aluminum and carbon dioxide are obtained.
Product yield is 99.7%. However, it is possible to obtain an even purer metal, which is used for technical purposes.
Application
The mechanical properties of aluminum are not good enough to be used in its pure form. Therefore, alloys based on this substance are most often used. There are many of them, we can name the most basic ones.
- Duralumin.
- Aluminum-manganese.
- Aluminum-magnesium.
- Aluminum-copper.
- Silumins.
- Avial.
Their main difference is, of course, third-party additives. All of them are based on aluminum. Other metals make the material more durable, resistant to corrosion, wear-resistant and malleable.
There are several main areas of application of aluminum both in pure form and in the form of its compounds (alloys).
- For making wire and foil used in the home.
- Cookware making.
- Aircraft industry.
- Shipbuilding.
- Construction and architecture.
- Space industry.
- Building reactors.
Together with iron and itsaluminum alloys - the most important metal. It is these two representatives of the periodic system that have found the most extensive industrial use in human hands.
Properties of aluminum hydroxide
Hydroxide is the most common compound that forms aluminum. Its chemical properties are the same as those of the metal itself - it is amphoteric. This means that it is capable of exhibiting a dual nature, reacting with both acids and alkalis.
Aluminum hydroxide itself is a white gelatinous precipitate. It is easy to get it by reacting an aluminum s alt with alkali or ammonium hydroxide. When reacted with acids, this hydroxide gives the usual corresponding s alt and water. If the reaction proceeds with alkali, then aluminum hydroxocomplexes are formed, in which its coordination number is 4. Example: Na[Al(OH)4] - sodium tetrahydroxoaluminate.
