One of the most convenient in handling materials are metals.Among them also have their leaders.For example, the basic properties of aluminum have long been known to people.They are so suitable for use in the home, that the metal has become very popular.What are the properties of aluminum as a simple matter and the atom, look at this article.
history of the discovery of aluminum
man has long been known to the compound of the metal - potassium alum.It was used as a tool that can swell and link the components of the mixture, it was necessary and dressing of leather products.The existence of pure alumina became known in the XVIII century, in the second half.However, the pure compound was obtained.
Managed the highlight of his metal chloride first scientist HC Oersted.It has processed amalgam, potassium salt and isolated from a mixture of gray powder, which was pure aluminum.
Then it became clear that the chemical properties of aluminum manifested in its high activity, strong resilience.Therefore, for a long time with him no longer worked.
However, in 1854, the Frenchman was able to get Deville bullion metal by electrolysis of molten.This method is relevant to this day.Especially valuable material mass production began in the XX century, when there were solved the problem of obtaining a large amount of power in the workplace.
Today the metal - one of the most popular and used in construction and household industries.
General characteristics of the aluminum atom
If characterize the element in question on the situation in the periodic table, it is possible to select multiple items.
- serial number - 13.
- Located in the third period, the small, the third group, the main subgroups.
- atomic mass - 26.98.
- number of valence electrons - 3.
- configuration of the outer layer is expressed by 3s23p1.
- Item Name - aluminum.
- Metal properties are strong.
- isotopes in nature does not have to exist only in one form, with the mass number 27.
- chemical symbol - AL, in the formula is read as "aluminum".
- degree of oxidation alone, is three.
chemical properties of aluminum are fully confirmed its electronic structure of the atom, because having a large atomic radius and a low electron affinity, it can act as a strong reducing agent, as well as all active metals.
Aluminium as a simple matter: the physical properties
Talking about aluminum, as a simple matter, it is a silvery-white lustrous metal.In the air is rapidly oxidized and covered with a dense oxide film.The same thing happens under the action of concentrated acids.
presence of such features makes products from the metal resistant to corrosion, which, of course, very convenient for people.Therefore, this is widely used in construction is aluminum.The properties of materials are also more interested in the fact that this metal is very light, with strong and soft.The combination of these characteristics is not available to each substance.
There are several basic physical properties that are characteristic of aluminum.
- high degree of malleability and ductility.From this metal manufactures lightweight, durable and very thin foil, it is rolled into wire.
- Melting point - 660 0C.
- Boiling point - 2450 0C.
- Density - 2.7 g / cm3.
- face-centered crystal lattice volume, metal.
- Type of connection - metal.
Physical and chemical properties of aluminum define its field of application and use.If we talk about the domestic side, that play an important role it already considered above characteristics.As a lightweight, durable and anti-corrosive metal, aluminum is used in aircraft and shipbuilding.Therefore, these properties are very important to know.
chemical properties of aluminum
In terms of chemistry, the metals - a strong reducing agent that is capable of exhibiting high chemical activity, as a pure substance.The main thing - is to remove the oxide film.In this case, the activity increases dramatically.
chemical properties of aluminum as a simple substance is determined by its ability to react with:
With water, he does not react under normal conditions.Thus from halogen without heating only reacts with iodine.For other reactions, the desired temperature.
There are examples that illustrate the chemical properties of aluminum.The equations of reaction with:
- acids - AL + HCL = AlCL3 + H2;
- alkalis - 2Al + 6H2O + 2NaOH = Na [Al (OH) 4] + 3H2;
- halogens - AL + Hal = ALHal3;
- gray - 2AL + 3S = AL2S3.
In general, the most important properties of the material - a high capacity for recovery of other elements from their compounds.
reducing properties of aluminum are easily traced to reaction with other metal oxides.It easily removes them from the material and allows there in plain sight.For example: Cr2O3 + AL = AL2O3 + Cr.
In metallurgy there is a whole procedure for the preparation of substances based on these reactions.It is named aluminothermy.Therefore, in the chemical industry active element is used for other metals.
Distribution in nature
to disseminate other metal elements aluminum ranks first.Its in the earth's crust contains 8.8%.If we compare with non-metals, then it will be the third place, after oxygen and silicon.
Due to the high reactivity does not occur in pure form, but only a part of various compounds.For example, a plurality of known ores, minerals, rocks, which include aluminum.However, it is only produced from bauxite, the content of which in nature is not too large.
most common substances containing the metals:
- aluminum silicates;
- basalts and others.
in a small amount of aluminum is required to part of the cells of living organisms.Some types of moss and sea creatures are able to accumulate this element in your body for life.
Physical and chemical properties of aluminum make it possible to get it in only one way: by electrolysis of a melt of the corresponding oxide.However, this process is technologically complex.Melting AL2O3 than 2000 0C.Because of this, it is directly subjected to electrolysis is not obtained.Therefore, we proceed as follows.
- mined bauxite.
- cleanses them of impurities, leaving only alumina.
- then melted cryolite.
- added to the oxide.
- This mixture elekrolizuyut obtain pure aluminum and carbon dioxide.
The yield is 99.7%.However, to attain and even cleaner metal which is used for technical purposes.
mechanical properties of aluminum is not so good to use it in its pure form.Therefore, the most commonly used alloys based on this substance.There are many, can be called the most basic.
main difference - is, of course, a third-party agents.All of the foundation is aluminum.Other metals also make the material more durable, corrosion resistant, wear resistant and pliable processed.
There are several main applications of aluminum in pure form or in the form of its compounds (alloys).
- For the manufacture of wire and foil used in everyday life.
- Making dishes.
- Construction and architecture.
- space industry.
- Create reactors.
Together with iron and aluminum alloys - the most important metal.These are the two representatives of the periodic system have found the most extensive industrial use in human hands.
properties of aluminum hydroxide
hydroxide - the most common compound that forms aluminum.Its chemical properties are the same as in the metal itself, - it amphoteric.This means that it is able to exhibit the dual nature reacts with both acids and alkalis.
itself aluminum hydroxide - a white gelatinous precipitate.Get it easily by reacting an aluminum salt with an alkali or ammonium hydroxide.When reacted with an acid active hydroxide gives the corresponding salt, and ordinary water.If the reaction proceeds with an alkali, the formed aluminum hydroxocomplexes in which its coordination number is 4. Example: Na [Al (OH) 4] - tetragidroksoalyuminat sodium.