What allotropy?

Reasons variety of organic compounds - the ability of carbon atoms to form a variety of chains and rings are interconnected.That is the phenomenon of isomerism.And the reason for the variety of simple inorganic substances?It turns out that this question can be answered by considering what allotropy.It is from this natural phenomenon in the world of chemical elements bind the existence of different forms of simple connections.

What allotropy?

answer to this question can be so.This phenomenon of existence of the same chemical element in the form of several single substances.That is, if the cells in the periodic table 118, it does not mean that in nature the same number of atoms.Each of the elements (almost all) have one or more species or allotropic modifications.

What distinguished these substances?The reasons for the phenomenon in two basic:

• different number of atoms in the molecule (allotropy composition);
• unequal structure of the crystal lattice (allotropy form).

Often this concept is associated with the term polymorphism.However, there is a difference between them.What allotropy?This modification of the chemical element in different simple substances, regardless of whether the state of aggregation in which it is located.While polymorphism - a concept that is applicable only to a crystalline solid.

different allotropic modifications of the compounds are usually denoted by Latin letters in front of their name.Alpha is always placed before the form that has a minimum melting point, boiling point.Next in alphabetical order and an increase in performance, respectively.

Although the chemical element in the basis of simple substance the same properties modifications differ significantly from each other, and both physical and chemical.The easiest form allotropic forms:

• non-metals (except for halogen and inert gases);
• semimetals.

Least studied allotropy metals, as they are reluctant to form such modifications and not all.Total to date there are more than 400 different forms of simple substances.The more oxidation characteristic of the element, the higher the number for a known allotropic modifications.

Altered Carbon

carbon allotropes - is the most common and striking example illustrating the phenomenon in question.After all, this element is capable of forming compounds of several varieties, differing in the structure of the crystal lattice.This image of a simple substance such polar opposites in their properties that decisions can only wonder of nature.

So carbon allotropes include the following modifications.

1. What is carbon allotropes, can be traced to his next form that is radically different from the previous one.This graphite.Very soft material that can easily flake off and leave a distinctive mark on the paper.Therefore, it is used for the manufacture of slate pencils in pencil.The structure of this form - a hexagonal layer.Connections between layers are weak, easily torn, the low density of the material.Graphite is used for the production of synthetic diamonds as the solid lubricant, for the manufacture of electrodes as plastics filler, and also in nuclear reactors.
2. Fullerenes - another proof that there allotropy.Chemistry of these compounds is similar to that of the aromatic hydrocarbons.It is represented by the structure of their closed convex polyhedra, resembling a soccer ball.Fullerenes are applied as a semiconductor in the art for the production of superconducting compounds as photoresist and the like.
3. Lonsdale and tserafit - two crystalline allotropic modification of carbon.It was opened recently.The properties are similar to diamond, with no impurities can be even several times harder.
4. Coal and soot - allotropy amorphous substances.Used as fuel, lubricants, filters and so on.According to the content in the nature of the most common of all the modifications of carbon.

Diamond

the hardest of all known substances to date, estimated at 10 points on the Mohs scale.The crystalline form of carbon whose structure has the form properly interconnected into a network of tetrahedral units.

Diamond is able to scatter light very well, so you can use it as a piece of jewelry (diamonds).Due to its extreme hardness, is used for cutting and welding, drilling, grinding and polishing.Today adjusted production of artificial diamonds used in industry.

Other species

Also, there are several varieties of this element:

• nanotubes;
• nanofoam;
• Astrolite;
• nanofibers;
• glassy;
• graphite;
• carbine;
• nanobuds.

Unconfirmed, but the existence of the alleged form of simple carbon compounds: chaoit, carbon and metal dicarbon.

Allotropy oxygen

This nonmetal two simple forms of matter:

• oxygen gas (under normal conditions), the formula of which O2;
• ozone gas, an empirical reflection of the composition of which O3.

Obviously, here is the main reason for the existence of modifications - the molecule.Normal oxygen - the foundation of life of all living beings (except for anaerobic bacteria).He is an active participant in the gas exchange, the source of energy for all vital processes.Chemically - oxidant, which is using a variety of reactions.

Ozone is formed in nature or special laboratory equipment ozonizers of air oxygen under the influence of a strong electrical discharge.In natural conditions - it's lightning.At low concentrations of trace has a pleasant smell of freshness (after the storm always felt in the air).It is a very strong oxidant, bleach, chemically active.

Modifications phosphorus

Allotropy is similar to that of oxygen and phosphorus.It also has about 11 different versions, different number of atoms in the molecule, and therefore, a chemical bond and properties.There are three stable forms and the rest of nature, and found virtually no decay.

1. White phosphorus.Formula his P4.The substance resembling white soft paraffin or slightly yellowish color.It is easy to melt, turning into poison gas.
2. Red phosphorus - a paste, which has an unpleasant odor.Formula - Pn.This polymer structure.
3. Black phosphorus - oily to the touch weight, which is black and completely soluble in water.

Modifications metal

What allotropy metals can be found on the example of iron.It exists in the form of:

• alpha;
• beta;
• gamma;
• sigma shape.

Each differs from the previous structure of the crystal lattice and, accordingly, properties.For example, the alpha-form - ferromagnetichna and beta -paramagnetik.

general, of all known metals allotropic modification form of 27 chemical elements.

Allotropy tin

interesting that the alpha-form - a gray powder, which exists only at low temperatures.Beta-form, on the other hand, metal, silver-white, soft and ductile.There is a high performance temperature - up to 161 ° C.One form is readily converted to the other in vivo, if degree difference.