Atomic mass of silver: The relative atomic mass of silver is 107.8682
Silver (Argentum) is a type of transition metal, with the chemical symbol Ag. Silver is one of the metals known and utilized in antiquity, and it is an important precious metal. Silver in nature, there are monomers, but the vast majority of them are in the form of chemical compounds present in the silver ore. The physical and chemical properties of silver are more stable, thermal and electrical conductivity is very good, soft, rich ductility, its reflectivity is very high, up to 99% or more, there are many important uses.
Name source:
Silver's chemical symbol Ag, from the Latin name of silver Argentum, is "light-colored, bright" means. The word silver belongs to the Burgundy family of characters. In the Burgundy family, the character Burgundy is both a sound and a meaning character. The characters of the Burgundy family are all related to the meaning of "boundary" and "limit". The original meaning of silver is "a metal whose value is close to that of gold".
Isotopes:
Silver in nature is silver 107 and silver 109, with silver 107 being the most abundant (51.839%). The two isotopes of silver have nearly the same abundance, which is rare in the periodic table. Silver*** has 28 isotopes (from Ag 93 to Ag 130) most of which have half-lives of less than three minutes.
Applications:
Silver applications: Sterling silver is a beautiful silvery-white metal that is very malleable and has the highest electrical and thermal conductivity of any metal. Silver is often used to make extremely sensitive physical instrument components, all kinds of automated devices, rockets, submarines, computers, nuclear devices, and communication systems, all of which have a large number of contact points made of silver.
During the period of use, each contact has to work millions of times, and must be wear-resistant and reliable to withstand the rigors of the work, silver can fully meet the requirements of all kinds of requirements. If rare earth elements are added to silver, the performance is even better. With this kind of silver with rare earth elements made of contact points, life can be extended several times. The most important compound of silver is silver nitrate. In medicine, the aqueous solution of silver nitrate is often used as eye drops.
Electrical and electronic materials:Electrical and electronic appliances are the industries that use the largest amount of silver, and their use is categorized into electrical contact materials, composites, and soldering materials. Silver and silver-based electrical contact materials can be divided into: pure silver, silver alloys, silver - oxide class, sintered alloy class. The world's annual output of silver and silver-based electrical contact materials is about 2,900 to 3,000 tons.
Composites are materials prepared using composite technology, divided into silver alloy composites and silver-based composites. From the silver-saving technology, silver composite materials is a class of promising new materials. Silver welding materials such as pure silver solder, silver - copper solder.
Photographic materials; silver halide photographic materials is one of the largest amount of silver in the field. Production and sales of the largest volume of several photographic materials are photographic film, photographic paper, X-ray film, fluorescent information recording film, electron microscope photographic soft film and printing film. In the 1990s, the world's photographic industry uses about 6,000 to 6,500 tons of silver.
As a result of the development of electronic imaging, digital imaging technology, so that the amount of silver halide photographic materials have been reduced, but the application of silver halide photographic materials in some aspects of the application is still irreplaceable, there is still a lot of market space.
Chemical materials: silver in this regard, there are two major applications, one is used as a catalyst, such as widely used in redox reactions and polymerization reactions, used to deal with sulfide-containing industrial waste gas. The second is the electronic plating industry agents, such as silver paste, silver potassium cyanide, etc..
Craft jewelry: silver has an attractive white luster, high chemical stability and collection of ornamental value, favored by the people, so there is a "woman's metal" of the beauty of the name, widely used as jewelry, decorations, silverware, tableware, congratulatory gifts, medals and commemorative coins. Silver jewelry in developing countries have a broad market, silver tableware is very popular with families.
Silver commemorative coins are beautifully designed, low mintage, value-added function, by the coin collectors and coin investors, the 20th century, the 1990s only minting silver each year to stay in the 1000 ~ 1500t up and down, accounting for the consumption of silver about 5%.
Role in living organisms: Silver ions and compounds show toxicity to certain bacteria, viruses, algae and fungi, but are almost completely harmless to the human body. This bactericidal effect of silver makes it possible to kill organisms outside the living body. However, silver is difficult to test and standardize.
Hippocrates described silver's usefulness in treating and preventing disease. The Phoenicians used silver bottles to hold water, wine, and vinegar to prevent the liquids from spoiling, and in the early 1900s, silver coins were placed in milk to prolong its freshness. The sterilization mechanism of silver has long been debated and explored, but has not yet been conclusively determined.
One good example is the microdynamic effect, which successfully explains the effect of silver ions on microorganisms, but not on viruses. Silver is added in large quantities to gels as well as bandages. The antimicrobial properties of silver are derived from silver ions. Because silver ions form strong bonds with substances used by microorganisms for respiration (e.g. molecules containing oxygen, sulfur, and nitrogen), these substances become unavailable to the microorganisms, which suffocate and die.
Prior to the invention of antibiotics, silver-related compounds were used in World War I to prevent infections. New applications of silver as a broadly useful antimicrobial agent are underway. One aspect of this is the dissolution of silver nitrate in alginate, which is used to prevent infections in wounds, especially burn wounds.
In 2007, a company designed a glass with a silver-plated surface, which is claimed to have good antimicrobial properties. In addition to this, the U.S. Food and Drug Administration (FDA) approved the use of an airway catheter with a silver-plated interior, as studies have shown it to be effective in reducing catheterized pneumonia.
Silver is not toxic to the human body, but prolonged exposure to the metal and to non-toxic silver compounds can lead to silicosis. Because of changes in body pigmentation, the surface of the skin will appear grayish blue. Although non-toxic, it still affects the appearance.