19 facts about graphene
This increasingly popular material, which is a flattened form of carbon arranged in cubic structures, may revolutionize our world and the state of cur ...
Silver is one of the first metals discovered by man, it has been known since antiquity. The Egyptians valued them more than gold. It was used to make decorations, dishes, and cutlery, and its valuable medicinal properties were quickly realized. As new deposits were discovered, they became more and more common, and even undesirable for gold seekers, often confused with platinum, which was contemptuously called "silver". This metal has been used to produce coins for centuries and is the most common raw material used for this purpose. As science and technology developed, a number of its valuable properties were discovered and learned, as a result of which it has found many applications and is an indispensable metal in many fields.
The Latin name for silver is argentum.
Its color misled gold seekers who, finding a gold nugget combined with a silvery metal, were mistakenly convinced that it was silver and treated it quite contemptuously. They were unaware that in this case, they were often dealing with platinum.
It is also found in the ores: argentite (a rare mineral from the sulfide group), chlorargyrite (a very rare mineral from the halide group), and pyrargyrite (a mineral from the sulfur-salt group, very rare). The main sources of silver are copper, copper-nickel, gold, lead, and lead-zinc ores.
Silver is mined in Mexico, Peru, China, Australia, Chile, Poland, Russia, Bolivia, USA, Argentina, Canada, Kazakhstan, India, Turkey, Sweden, Guatemala, Morocco, Indonesia, Iran, and Papua New Guinea.
It is a very ductile and malleable metal with a shiny luster and can be easily polished.
However, it cannot be used for the production of electrical cables because it is subject to corrosion due to the presence of sulfur oxides in the atmosphere. Its price is also important. During World War II, due to the copper shortage, silver was used in electromagnets to enrich uranium.
Aluminum (Al) reflects ultraviolet light even more.
However, it becomes dull upon contact with ozone, hydrogen sulfide, and air polluted with sulfur compounds. Silver halides slowly decompose when exposed to light.
Purity levels above 99.999 percent can also be found.
925 silver alloyed with copper is used to make jewelry, dishes and cutlery, medals, and musical instruments, e.g. flutes. Silver guarantees a special, characteristic sound color. Flutes are also made of gold and platinum.
Coins were produced from it as early as the 7th century BC. They were made in an ancient country called Lydia, from an alloy of silver and gold called electrum.
The British pound was initially worth 1 pound of 925 silver jewelry.
It is used there to obtain silver halides (primarily silver bromide) used as photosensitive substances.
They are also used in analytical chemistry, e.g. to detect aldehydes (Tollens test).
Compounds of other heavy metals, such as copper, lead, or mercury, also have such properties, but silver compounds are not as harmful to humans. They kill many microorganisms in vitro. Silver ions can change the structure of cell walls and the nuclear envelope, disorganizing bacterial cells. Silver also binds to bacterial DNA and RNA, preventing them from replicating.
Silver is the only catalyst that allows the conversion of ethylene into ethylene oxide, which then undergoes hydrolysis to produce ethylene glycol, used to produce polyester.
Its importance in medicine lies in the use of strong antibacterial properties. Before antibiotics were available, silver compounds were used to prevent infections during World War I.
Silver is also currently used in disinfectants and disinfectants, as well as preparations to prevent infection of wounds and burns.
Taking too large doses of such silver may lead to argyrosis, and discoloration of the skin, eyes, and mucous membranes to a blue-gray color, which is an irreversible process.
The Lower Silesian copper and silver deposits, exploited by KGHM Polska Miedź, were in second place among global silver producers in 2019. The KGHM plant is the largest silver mine in the world (according to the World Silver Survey 2020 report). The main recipients of silver produced by the company are Great Britain, the USA, and Belgium.
