Man has been using silver for a longtime. Archeologists have found evidence of its usage dating back 5,000 years. Its name comes from the Anglo-Saxon name for the element “seolfor”, while its symbol (Ag) comes from its Latin name “argentum”.
The metallic element with atomic number 47 belongs to d-block of elements. Within the periodic table, silver occurs in period 5 and group 11 (unofficially known as the coinage metal group).
Important physical properties of this element include its melting point of 961.78 °C (1234.93 K, 1763.20°F) and its boiling point of 2162.0 °C (2435 K, 3924 °F). Silver has a density of 10.501 grams per cubic centimeter and an atomic weight of 107.8682. The ionization energy of silver is 7.576 eV and its oxidation state is +1.
Silver occurs as a pure metal as well as in silver mineral ores such as argentite and horn silver. Trace amounts of silver occur in other mineral ores. Commercial production of silver occurs as a by-product of the extraction of other metals such as lead, gold and copper from such ores. It is quite a rare element with a crustal abundance of 0.075 milligrams per kilogram.
Silver does not react with pure air or water. However, trace quantities of sulfur present in the atmosphere causes tarnishing with the build up of a layer of black silver sulfide.
This very malleable and ductile metal has the highest electrical and thermal conductivity of all metals as well as the lowest contact resistance. These properties make the metal of value in the electronic industry where it is used in the manufacture of solders, electrical contacts and printed circuit boards.
Silver is a very good reflector of light. This makes it valuable in the production of mirrors. Silver mirrors require a protective covering to prevent tarnishing.
Prior to the discovery of antibiotics silver had a long history in the treatment of wounds. It also prevented bacterial spoilage of drinking water and milk. As such, it was known by Hippocrates and mentioned in the works of Paracelsus. Today with the emergence of bacterial resistance to many antibiotics, the use of colloidal silver products for the treatment of some infections is once again regaining acceptance.
The compound silver nitrate, a light sensitive compound, is used in photography for the production of film and photographic paper.
Los Alamos National Laboratory Chemistry Division
Clear Springs Press
Jefferson Laboratories Science Education website