Each chemical element of the periodic system and educated them simple and complex substances are unique.They have unique properties, and many are making undeniably significant contribution to human life and existence in general.No exception and the chemical element tin.
Meeting people with the metal goes back to antiquity.This chemical element has played a crucial role in the development of human civilization to the present day properties of tin are widely used.
Tin history
first mention of this metal having, as people previously thought, even some magical properties, can be found in the biblical texts.Crucial to improving the lives of tin played during the "Bronze" century.At the time, most durable metal alloy that possessed the man was bronze, it can be obtained in a chemical element copper is added tin.For several centuries, this material produced everything from tools and ending with the jewelry.
After opening the properties of the iron alloy of tin has not ceased to be used, of course, it does not apply unabated, but the bronze, as well as many other alloys are actively involved in the industry today, man, technology, and medicine, along with the metal salts, such assuch as stannous chloride, which is obtained by reacting tin with chlorine, this liquid boils at 112 degrees Celsius, well soluble in water forms crystalline hydrates in air and smokes.
position of the element in the periodic table
chemical element tin (Latin name stannum - «stannum" written symbol Sn) Dmitri Ivanovich Mendeleev arranged on the right at number fifty in the fifth period.Has a number of isotopes, the most common - the isotope 120. This metal is also in the main group of the six groups, together with the carbon, silicon, germanium, and Flerov.Its location predicts amphoteric properties equally inherent tin and acidic and basic characteristics, which will be described in more detail below.
in the periodic table also contains the atomic mass of tin, which is equal to 118.69.Electronic configuration 5s25p2, that the composition of complex substances allows the metal has an oxidation state +2 and +4, giving only two electrons with the district or sub-level four and s- and p, completely devastating the entire outer layer.
Electronic characteristic element
According perinuclear space of the atomic number of the tin atom contains as many as fifty-electrons, they are located on five levels, which in turn are split into a number of sub-levels.The first two have only the s- and p-sub-levels, and since third goes triple splitting into s-, p-, d-.
Consider an external electronic level, since it is its structure and filling of electrons determine the chemical activity of an atom.In the unexcited state element has a valence equal to two, the transition in the excitation of an electron from the s-sublevel to the vacant seat district sublevel (it can contain a maximum of three unpaired electrons).In this case, the tin has a valence and oxidation - 4, since no paired electrons, and therefore in the process of chemical interaction on their sublevels nothing holds.
metal simple substance and its properties
simple substance is a metal tin, silver, refers to a group of low-melting.Metal soft, relatively easily amenable to deformation.A number of features inherent in this metal tin.The temperature is below 13.2 degrees Celsius is the boundary of transition metal modification of tin powder, which is accompanied by a change in color from silvery-white to gray, and a decrease in the density of matter.Tin melts at 231.9 degrees, and boils at 2270 degrees Celsius.The crystal structure of the tetragonal white tin explains the characteristic crunching metal during its bending and heat inflection in place by friction substance crystals against each other.Gray tin has a cubic system.
chemical properties of tin have a dual essence, it comes in both acidic and basic reaction, showing amphoteric.Metal reacts with alkalis, and acids such as sulfuric acid and nitric acid, is active in the reaction with the halogen.
tin alloys
Why often used instead of pure metal alloys with a certain percentage of the constituent components?The fact that the inherent properties of the alloy, which do not have an individual metal or these properties are much greater (e.g., conductivity, resistance to corrosion, passivation or activation of the physical and chemical characteristics of metals, if necessary etc).Tin (photo shows a sample of pure metal) is a part of many alloys.It can be used as an additive or base material.
Currently, there is a large amount of alloy metal such as tin (price for them varies widely), look at the most popular and used (the use of certain alloys, it will go to the appropriate section).In general, stannuma alloys have the following characteristics: high ductility, low melting point, a small hardness and strength.
Some examples of alloys
- alloy of tin and lead with some dopants (antimony, copper, cadmium, zinc, silver, indium) - the so-called tin solder, the percentage of stannuma it to achieve the best bondingProperties must be 49-51 or 59-61 percent.The strength of the connection ensures the formation of a solid solution of tin fastened with metal surfaces.
- Garth - an alloy of tin, lead and antimony - the foundation typographical paint (which is why it is not recommended to wrap foods in newspaper, to prevent ingress of unwanted concentrations of these metals).
- Babbit - an alloy of tin, lead, copper and antimony - is characterized by a low coefficient of friction, high wear resistance.
- indium tin - fusible material, which is characterized by refractoriness, corrosion resistance and a large strength.
important natural compounds
Tin forms a series of natural compounds - ores.Metal forms 24 mineral compounds, the most important for the industry is tin oxide - cassiterite, and the trails - Cu2FeSnS4.Tin dispersed in the earth's crust, and compounds formed by them have magnetic origin.The industry also uses salt poliolovyannyh acids and tin silicate.
Tin and humans
chemical element tin is a trace element in its quantitative content in the human body.Its main cluster is in the bone, where the normal metal content it contributes to the timely development and overall functioning of the locomotor system.Besides bone, tin concentrates in the gastrointestinal tract, lung, kidney and heart.
Importantly, the excessive accumulation of the metal can lead to an overall poisoning organism and longer action - even in adverse gene mutations.Recently, this problem is quite relevant, since the environmental situation leaves much to be desired.A high probability of intoxication with tin residents of megacities and areas around industrial zones nearby.In most poisoning occurs by the accumulation in the lungs tin salts, such as stannous chloride, and others.At the same time the lack of trace elements can cause growth retardation, loss of hearing and hair loss.
Application
metal is commercially available in many steel mills and companies.It is produced in the form of ingots, rods, wire cylinders, anodes of pure simple substance such as tin.The price ranges from 900 to 3000 rubles per kg.
Tin pure rarely used.Mostly used alloys and compounds - salt.Tin solder is applied in the case of bonding parts which are not exposed to high temperatures and strong mechanical stress, made of copper alloy, steel, copper, but is not recommended for made of aluminum or aluminum alloys.The properties and characteristics of the tin alloys are described in the relevant section.
solders for soldering chips used in this situation as ideal alloys based on a metal such as tin.Photo shows the process of applying tin-lead alloy.With it, you can thin enough work.
Due to the high corrosion resistance of the tin it is used for the manufacture of tinned iron (tinplate) - cans for food products.In medicine, in particular in dentistry, tin involved to perform dental fillings.Tin coated brownies pipes made from alloys bearings.Invaluable contribution to this important matter and in electrical engineering.
Aqueous solutions of tin salts as fluoroborates, sulphates and chlorides are used as electrolyte.Tin oxide - a glaze for ceramics.Through the introduction of plastic and synthetic materials of various derivatives of tin it is impossible to reduce their flammability and the release of harmful fumes.
