Silver (metal): properties, photo. How to identify silver
Silver is metal (see photo below), which is one of the rare chemical elements. Most often it is used for making jewelry.
However, silver is a metal with an extensivesphere of application. Without it, cinematography and medicine, photography and engineering can not do without. Silver is also used as a means of investment. In this regard, it is not inferior to gold at all. On the contrary, silver is often used by investors to diversify risks.
Silver as a chemical element
Silver is metal or non-metal? Of course, metal. And this can be confirmed by the periodic system compiled by Mendeleev. You can find this metal in its first group. The atomic number of silver is 47. Its atomic mass is 107.8682.
Silver is a noble metal, which consists oftwo isotopes. This is 107Ag and 109Ag. In addition, more than thirty-five radioactive isomers and silver isotopes are discovered by science, whose mass numbers range from 99 to 123. The longest-lived of them, 109Ag, has a half-life of 130 years.
History of origin of the name
Silver - metal, which attracted people's attentionback in ancient times. The name "silver" comes from the Sanskrit word "argenta". It means "light". The Latin "argentum" (silver) has the same roots. But in this language it means "white".
Silver is a noble metal, and the alchemists did not bypass it. In the distant past, they developed a method of reducing this natural element.
In Russian, the metal in question isthe name "silver", in English it sounds like "silver", in German - "zilber". All these words originated from the ancient Indian "sarpa", which meant the moon. The explanation is quite simple. The glitter of silver reminded people of the light of a mysterious heavenly body.
History of noble metal
Silver is familiar to mankind from time immemorialtimes. The exact date of its discovery is unknown. However, written sources indicate that jewelry from this metal was made by ancient Egyptians. At that time, silver was less common than gold, and was therefore much appreciated.
The first mines for the extraction of this natural element were founded by the Phoenicians even before our era. Developments were conducted in Cyprus and Corsica, as well as in Spain.
As jewelry during that periodsilver was valued fabulously expensive. For example, in ancient Rome, the peak of luxury was a saltcellar made of this beautiful metal. Why is such a common element in nature so appreciated by people? The fact is that mankind knew only native metal. It was very difficult to find him. This interfered with the sulfide, which covers all the nuggets with a dark coating.
A turning point in the history of silver steelexperiments conducted by medieval alchemists. The purpose of their experiments was to obtain gold from any other metal. Thus, Europeans managed to extract silver from its compounds with various chemical elements (arsenic, chlorine, etc.).
In the history of silver, a significant role was played by suchpersonality, like Scheele, Paracelsus, etc. These scientists studied silver (metal), the properties of its compounds. As a result, interesting conclusions were drawn. Thus, the fact that this natural element possesses disinfecting qualities, which were seen back in antiquity, was confirmed. For example, Egypt's healers used silver plates to treat wounds to avoid the formation of pus in them. Antibacterial properties of this metal were also highly appreciated by the aristocracy. So, for centuries, silverware was a synonym for quality and expensive dishes. By that time mankind had improved the methods of mining the described metal, which made it much cheaper.
Silver was also used as a settlementfacilities. For this, coins were made from it. It is the silver of Russians owed the name of the state monetary unit. For calculations in Russia the necessary quantity from silver ingots was cut off. That's the word "ruble" and went into use.
Silver - metal is relatively plastic and soft. Of its one gram can be drawn the finest wire, the length of which will be almost two kilometers.
Silver is a heavy metal having a density of 10.5 grams per cubic centimeter. For this indicator, this element is only slightly inferior to lead.
Silver is a metal that has no equal in electrical and thermal conductivity. That is why a spoon made of this substance is heated up so quickly in a glass of hot water.
What other properties does silver have? Which metal is most often used by jewelers? Silver is a material with which it is relatively easy to work. This is due to its ability to melt at a temperature of 962 degrees. This value is relatively low. In addition, silver is easily fused with many other metals to change its characteristics. So, copper is able to increase the hardness of this plastic natural element. With its addition, silver becomes suitable for the manufacture of a variety of products.
This amazing element described in detail inhis works D.I. Mendeleev. He also pointed out how to determine metal silver among others. First of all, the noble component stands out with its more white and pure color. In addition, the silver is so soft that it can easily be erased.
How to distinguish silver from metal in ready-madeproducts? Rings, chains, spoons, forks, coasters and old coins with time start to fade and even turn black. The reason for this is the impact on them of hydrogen sulphide. The source of the latter is not only rotten eggs. Hydrogen sulfide releases rubber and some polymers. A chemical reaction occurs when there is a certain amount of moisture. On the surface of the products, a very thin film of sulphide is formed. At first, thanks to the play of light, it seems iridescent. However, gradually the sulphide film thickens. It turns dark, changes its color to brown, and then to black.
Silver sulphide can not be destroyed under strongheat, dissolve in alkalis and acids. If the film is not very thick, then it is removed mechanically. The product should be polished with a powder or toothpaste with soapy water to restore its shine.
How to distinguish silver from metal in other ways? For this, one should observe chemical reactions. A noble element can easily be dissolved in some acids. It is nitric and concentrated hot sulfuric, and also iodo- and hydrobromic acids. If the chemical reaction between silver and hydrochloric acid was carried out in the presence of oxygen, then the complex halides of the noble metal would result.
Silver will not interact with nitrogen andhydrogen. It does not react with carbon. As for phosphorus, it can act on silver, only reaching the temperature of red heat, at which phosphides are formed. But with sulfur, the noble metal interacts quite easily. When these elements are heated, a sulphide is formed. The same substance can be obtained in the event of exposure of gaseous sulfur to a heated metal.
The chemical reaction is of interestnoble metal with oxygen. Silver does not react with it, but it can still dissolve a significant amount of this gas. This property of metal when it is heated contributes to the appearance of a very dangerous, but at the same time, beautiful phenomenon. It's sprinkling of silver. This phenomenon was known back in ancient times.
Silver is a metal whose properties allowlike gold, it is easy to interact with royal vodka, as well as with hydrochloric acid, saturated with chlorine. As a result of this reaction, it falls into an insoluble precipitate, since a poorly soluble chloride is formed. These differences in the behavior of silver and gold are often used to separate them.
It is able to dissolve the lunar metal in dilute sulfuric acid. However, for this purpose, silver must be finely divided and contact with oxygen.
Noble metal can be dissolved in watersolutions of alkaline earth and alkaline metals, cyanides, if they are sufficiently saturated with air. The same reaction occurs when silver is contacted with an aqueous solution of thiourea, in which there are iron salts.
Lunar metal compounds, as a rule, havea positive first degree of oxidation. In some elements, this indicator reaches values of two or three. However, such silver compounds have no practical significance.
Silver is a metal (see photo below), which in living substances is six times less than in soils. In other words, this element is not considered biological.
However, a small number of positive ionssilver is sufficient for many processes. For example, since ancient times, the ability of low concentrations of this metal to have a bactericidal effect on drinking water is known. Even a small amount of ions, like 0.05 milligrams per liter, provides sufficient antimicrobial activity. Such water can be consumed without fear for one's health. It is interesting that her taste remains unchanged.
If there is 0.1 milligram in a liter of liquidions of silver, it can be mothballed for one year. But do not expose water to boiling. The high temperature leads to the fact that silver ions become inactive.
Bactericidal property of the noble elementallows to widely use it for the purpose of sterilizing drinking water. So, in some household filters there is an activated silvered coal. This component releases into the water negligible doses of curative ions.
Antimicrobial ability of silver finds itsapplication and disinfection of swimming pools. In them water is saturated with bromide of this metal. A low concentration of AgBr (0.08 mg / l) is harmless to humans and is harmful to algae and pathogenic microorganisms.
Than it is possible to explain bactericidal action of ionssilver? The fact is that they affect the vital activity of various microbes, interfering with the work of their biological catalysts. That's exactly how silver works. What metal is still capable of this? Such substances include, for example, mercury. It, like silver, is heavy metal, but much more toxic. Mercury chlorides easily dissolve in water, they are dangerous for human health. Copper also has similar properties.
Negative influence of silver
It often happens that a substance thatIt is useful for a person in small doses, it becomes disastrous in large quantities. To such elements it is possible to carry and silver. Experimentally proved that significant volumes of ions of this metal can reduce immunity in experimental animals, introduce negative changes in the nervous and vascular tissues of the brain. Even larger doses damage the liver, thyroid and kidneys. In practice, cases were recorded when a person was poisoned from drugs of silver, which was accompanied by severe mental disorders. Fortunately, this element is easily excreted by the body.
Pathological condition caused by lunar metal
In medical practice, an unusuala disease called argiria. It appears in a person in the event that for many years of his life he works with silver or its salts. These substances enter small amounts in the body, deposited in the connective tissues, as well as in the walls of the capillaries of the kidneys, bone marrow and spleen. The external symptoms of this pathology are convincingly confirmed by the pictures below.
Silver - metal, which graduallyaccumulates in the mucous membranes and in the skin, giving them a bluish or gray-green color. At the same time, it becomes especially bright on those parts of the body that are exposed to light. Sometimes the skin color changes so much that a person becomes like an African.
The development of argyria is very slow. Its first symptoms become noticeable after two or four years of constant work with silver. The most severe darkening is observed after tens of years. First of all, the color of the lips, temples, conjunctiva of the eyes changes. Then darken the eyelids. Sometimes gums and mucous membranes of the oral cavity, as well as nail holes, are colored. Sometimes argyria manifests itself in the form of small green-blue spots.
Get rid of this pathology and return the skinthe previous coloring is impossible. However, in addition to external cosmetic inconveniences, the patient does not complain about anything. That is why argyria can only conditionally be considered a disease. This pathology has its positive side. A person, literally soaked in silver, never suffers from infectious ailments. Healing ions kill all the pathogenic microorganisms that enter the body.
Silver is a non-ferrous metal, which is sometimes difficult to distinguish from similar in appearance. It is not easy to do this, but it is quite realistic.
Metal, like silver, can be whitegold, silver or aluminum. How can we distinguish them? To determine whether a product made of silver or white gold is made, only professionals familiar with the specifics of these metals can. Doing it yourself at home is not recommended.
Outwardly these two metals are very similar to each other. The fact is that in the alloy of white gold is a large percentage of silver. To distinguish products from these materials is capable only of a jeweler who will calculate the original in terms of density.
Silver is a non-ferrous metal, which is often confused withMelchior. The latter is an alloy of nickel, lead and copper. Often, nickel is the production component of silver of various technical samples. How to distinguish "metal for silver"? First of all, you need to carefully consider the existing product. There will not be a sample on a nickel-silver one. On such products put only the brand "MNC", which indicates the composition of the alloy (copper, nickel and lead). Silver differs from the alloy in density and weight. However, only a specialist can establish these characteristics. At home you can drop on the product with iodine solution. On silver after that there will be a stain, and on a silver-nickel there is no.
Often, they try to give away a noble metalaluminum. However, the latter has significant differences from silver in terms of density, gloss, hardness and color. Counterfeit products are attempted only in gates and various shops. Such decoration after a short socks begins to oxidize. You can distinguish silver from aluminum with a magnet. Noble metal does not attract him. In addition, any physical or chemical effect on aluminum causes a change in its color, appearance, and size deformation.
Silver and jewelry fashion
Thanks to the availability of this materiala large number of different decorations are performed. Is silver a precious metal or not? Yes, it is in the same group as gold and platinum. These are noble metals that are not subject to oxidation and corrosion. Precious they are called not only because of the unique properties, but also because of the small reserves contained in the earth's crust.
Silver is a universal material. It equally well suits both women and men who have different social status and age. Silver is perfectly combined with enamel, with gold. It looks wonderful precious and semiprecious stones, pearls, corals and ivory.
Ornaments from silver are suitable for any occasion. And from a wide variety of models, you can always pick up the product for a certain reason. In addition, according to ancient ideas about this metal, it is able to heal and soothe. That is why it is not worth while in our madly speedy century to deny ourselves the acquisition of a small joy.
To date, jewelers offer a hugequantity of the most various ornaments, a material for manufacturing of which was silver. Each of these products will certainly give a good mood. To find them in the window of a jewelry store is not difficult.
Silver is the lightest noble metal. Not surprisingly, the demand for jewelry from it is stable in all countries of the world. An important factor in the popularity of silver products is their color. After all, one of the most fashionable is clothing made of gray fabric with metallic outflow, as well as black and white. This trend has shifted to jewelry made of precious metals. High consumer demand for products in which silver is combined with sapphire, emerald, topaz, garnet, amethyst, tourmaline. Often, malachite and lazurite, agate and jasper, carnelian and chalcedony, amber and tiger eye are often used as insertions. Often silver is used to create rings and pendants with enamel, filigree, engraving and enamel.
All these ornaments have a wonderfulalternative. To create jewelry used metal, coated with silver. In appearance and in quality, such things are no different from those that are entirely made of noble material. One of the positive aspects is their price. She pleasantly surprises buyers. In addition, silver-plated ornaments will suit those who have sensitive skin. Such products do not cause any irritation and leave no residue when worn. Their quality is indicated by the fact that they do not rust and darken over time. Thus, silvered rings, chains, bracelets and pendants will be an excellent gift to a loved one or a friend. Their cost is quite acceptable, and the quality is excellent.