Gold, Platinum are well known as the most precious and expensive Metals available to us. Added to the list is the element Silver. Just like GOld, because of the scarcity of this element, along with other attractive properties such as the brilliant white shiny colour, ductility, malleability, and its resistance to the Atmospheric Oxidation, Silver has often been in high demand for the manufacturing of coins, jewelry and other valuable ornaments.
The ornaments made from Silver have dated back to as far as 4000 BCE. The tombs of the royal personage in the ancient times were found to be decorated with valuable ornaments made from GOld, Silver and other prized Metals. It is also believed that the money used in the ancient times were made from GOld and Silver.
Silver (Ag), is a chemical element, a lustrous white Metal that is prized for its decorative beauty and electrical conductivity. Silver is situated between copper (period 4) and GOld (period 6) in Group 11(Ib) and Period 5 of the periodic table, and its physical and chemical properties are intermediate between those two Metals.
Although Silver is widely distributed and available in nature, it still is scarce in comparison to other Metals. It is recorded that the Metal consists of only 0.05 part million of our Earth’s crust. Although, as different from the Metal GOld, the Metal can be extracted from many naturally occurring minerals. Most of the Silver that we find today are derived as the by-products from the ores that are mined in order to obtain other Metals. These ores that generally contain Silver in them are the lead ores, copper ores, cobalt arsenide ores etc.
History
It is believed that the mining of Silver started in 3000 BC . Slag heaps near the mine working areas in ancient Turkey and Greece show evidence of mining Silver. This Metal thus obtained was then refined by the procedure known as the cupellation , which was a process invented by the Chaldeans. The process involved heating the molten Metal inside a shallow cup. Over this cup they would blow a strong draft of air which would lead to the oxidation of other Metals such as lead, copper etc, while Silver would remain unaffected.
It is also believed that the rise of Athen had something to do with exploitation of the local Silver mines located in Laurium. Apart from this, it is noted that the German mines, in medieval times, would go on to become the main source for Silver to the Europeans.
The ancient civilizations of Central and South America were also said to have been practicing the mining of Silver. It is believed that rich deposits of Silver were often found in places like Peru, Mexico and Bolivia.
Appearance: it appears as a white lustrous Metal and is most commonly known for its decorative beauty and electrical conductivity.
Structure: It has face-centered cubic crystal structure
Elemental Properties of Silver
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The Silver atomic number is 47
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the Atomic weight of Silver is 107.868g
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Its melting point is 960.8 °c (1,861.4 °f)
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Its boiling point is 2,212 °c (4,014 °f)
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Silver has specific gravity, approximately 10.5 (20 °c
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68°f
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68°f)
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Oxidation states of Silver is +1, +2, +3
Physical Properties of Silver
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Silver is a very popular Metal too. Silver, like Gold, is a rare Metal and has great value, and is also traded in similar markets.
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Silver is also a common Metal with which to make jewelry owing to its scarcity and malevolence.
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Silver has also been used in dentistry for some time, although it had to be mixed with mercury as it is not quite as malleable as Gold.
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GOld is also a good conductor, and is used for galvanizing. It is also used in battery manufacturing and as a catalyst.
Chemical Properties of Silver
While coinage Metals are known to be oxygen-resistant in air, Silver will become tarnished by H2S(g)
()
Pure Silver Metal is Heat and Electricity ‘s best conductor. For jewellery and utensils, pure Silver would be too soft so it is usually alloyed with at least one other Metal. For example, sterling Silver is generally about 93% Silver and 7% other Metals, mostly copper.
Silver can be found in high concentrations such as argentite, Ag2SAg2S but most of it is recovered in other Metals such as copper refining processes. Most of the Silver compounds are light sensitive, and the photographic industry uses a lot of Silver bromide and Silver chloride.
Preparation of Silver
Extraction of Silver By Cyanide Process
Silver also occurs both in combined and free state. The most important Silver ores are: Argentite (Ag2S), Copper Silver look, Horn Silver, Ruby Silver. In some parts of India, the Silver ores are found alongside GOld ores.
The rock-argentinas (Ag2S) extracts GOld. The GOld extraction process is called cyanide process as sodium cyanide solution is used. The ore is crushed, compressed, and then treated with a solution of sodium cyanide. This reaction forms the cyanide sodium argento.
Sodium argento cyanide solution combines with zinc dust, which forms cyanozicate sodium tetra and precipitated Silver. The precipitated Silver is called Silver spongy.
To obtain pure Silver the spongy Silver is fused with potassium nitrate. The obtained Silver is then extracted by an electrolytic process.
Applications of Silver
As an Element
Silver has been used for many thousands of years by people all over the world, for jewellery, as money, and many other things.
Although it looks black it is called a white Metal. Also, the term Silver is used to talk of this color or shade of grey.
Silver is used in utensils, too. In dentistry, it may be used as an amalgam to fill teeth. Silver serves as a catalyst.
Energy
The Silver paste finds its use in the making of the solar panels. The Silver paste contacts that are printed on the photovoltaic cells, perform the role of capturing and carrying out the electrical current. This current that is produced takes place when the sun comes in contact with the semiconducting layer of the cell.
The reflectivity associated with Silver helps it perform another role in the domain of solar energy. The Silver reflects the solar energy into collectors
that go on to use the salts in order to generate electricity.
The use of Silver is also found in the production of nuclear energy. The Metal is employed in the control rods that help in capturing the neutrons and slow down the rate of the fission occurring in the nuclear reactors.
Medicine
Silver is incorporated into wound dressings in medicine, and used in medical devices as an antibiotic coating. External infections are treated with wound dressings containing Silver sulfadiazine or Silver Nanomaterials.
Silver is also used in some medical applications, such as urinary catheters (where preliminary evidence indicates that it decreases urinary tract infections associated with catheters) and in endotracheal breathing tubes.
Electronics
A very important and prominent use of this Metal is often found in electronics. The thermal and electrical conductivity of Silver is hard to be found or replaced by any other Metal. For example, small quantities of Silver are added as contacts in the electrical switches. So as to on the switch, one has to join these contacts, and the separation of the contact would mean that the switch is off. The current passes through only if the contact is joined. The automobiles are heavily influenced by this technique as they have numerous features , full of contacts, that control the electrical appliances present in them.
Silver is very important for conductors and electrodes in electronics because of its high electrical conductivity even when tarnished.
Jeweley and Silverware
Another very prominent role of this Metal is associated in the production of jewelry and Silverware. Traditionally, the luster, reflectivity and malleability of the Metal makes it a very sought after choice. Because of its extreme softness, this Metal is often alloyed with a base Metal like copper. Although this Metal is known to resist oxidation and corrosion, with time Silver can tarnish. But with a little polish it can easily gain back its luster.
Brazing Alloys
Silver – containing brazing alloys are used to brush Metallic materials, particularly alloys based on cobalt, nickel, and copper, tool steels, and precious Metals.
Catalysis
Silver Metal is a good catalyst for oxidation reactions; in addition, it is somewhat too good for most purposes, as finely divided Silver tends to result in complete oxidation of organic compounds to carbon dioxide and water, and therefore prefers to use coarser-grained Silver instead.
Photography
The photosensitivity of the Silver halides let their use in traditional photography, though now dominant is digital photography, which does not use Silver.