Periodic Table -> Silver

Silver


Silver Details

Silver Symbol: Ag

Silver Atomic Number: 47

Silver Atomic Weight: 107.870

What is Silver?

Silver (number 47, symbol Ag) is a chemical element that occurs in copper-nickel, gold, copper, lead-zinc, lead, and argentite ores. It is a transition metal that can be obtained from brittle silver and dark ruby and light ruby silver. In history, it was used to make coins and ornaments and was produced by separating silver from lead. It is a noble metal, along with gold, platinum, iridium, osmium, ruthenium, and palladium.

Occurrence
Deposits are found in different parts of the world, including countries such as Canada, Honduras, Bolivia, Mexico, Germany, and Norway. The major producers are the United States and Poland. The annual production is about 7,000 tonnes. High concentrations are found in sewage outfalls, metal mining, cloud seeding, and waste sites. Species living near mine wastes and electroplating plants are found to have higher concentrations of silver. It is also found in a variety of non-biological sources. Low concentrations are found in natural sources as well.

Properties
The element has several isotopes, including Ag-111, Ag-110, Ag-109, Ag-107, and others. There are 11 known isotopes. Some have a half life of about 25 seconds, others of over 130 years, and still others are stable. The element has high thermal and electrical conductivity and is malleable and ductile. In fact, this metal has the highest electrical conductivity. It is stable in water and air and has a metallic luster. Silver tarnishes in contact with hydrogen sulfide and ozone. The boiling point is 2,212 C (4,013.6 F) and the melting point is 962 C (1763.6 F). While silver is not chemically active, it reacts with sulfuric acid and nitric acid. There are sulfides, fluorides, and oxides, as well as explosive compounds such as silver fulminate which is sensitive to pressure and heat. The metal itself is stable in water.

Uses
Silver and its compounds have many commercial applications. It is used to make silverware and jewelry, including ornaments, pendants, and earrings. Silver is also used in the electronic, electrical, photographic, and other industries. Silver electrical contacts are used to manufacture keyboards. Printed circuits contain silver-based paints. The metal is also used to make batteries, contacts, brazing and dental alloys, and mirrors. It has applications in the clothing industry, medicine, and optics. It is also used to produce endotracheal breathing tubes and urinary catheters as well as for its antimicrobial properties. E174 which is a food additive also contains silver and is added to cookie decorations and coatings.


Health and Environmental Effects
While silver is non-toxic and is not considered a health hazard, its compounds are poisonous. Exposure increases the risk for argyria which causes blue skin discoloration. Miners, silver metal workers, and patients who take silver-based supplements are at risk especially after long-term exposure. Exposure usually occurs through inhalation, ingestion, and skin contact. Depending on the concentration, soluble salts can be lethal. Inhalation of silver salts can cause coma, confusion, staggering, and drowsiness. Side effects include respiratory problems, headache, and breathing difficulty. In laboratory settings, exposure results in brain, liver, and lung damage, eye and kidney damage, and anemia. Research suggests that chronic exposure may lead to nervous system damage and cardiovascular problems. In species, the highest concentrations are found in the kidneys, the digestive gland, and other internal organs. Concentrations in living organisms vary based on factors such as compounds found in water, the biosphere, salinity, water temperature, metabolism, and health. Other factors include reproductive stage, sex, size, and age. Some studies suggest that silver may be a carcinogen, and the metal does not have a biological role.

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