Silver is the fourth element in the periodic table, after copper and gold, with its symbol (Ag) derived from the Latin argentum, meaning “white and shining.” It is a coinage metal with properties closely resembling copper and gold.
Natural silver is found in the minerals argentite and tetrahedrite, usually associated with copper, lead, zinc and other sulfides. It is commonly reduced to pure silver by low heat from its ores.
Historically, the silver coinage industry became an important part of society and was one of the driving forces behind the development of civilizations in Mesopotamia and the Near East, as well as in ancient Greece, Rome and Carthage. Its value also enabled the mercenary armies of these cultures to hire soldiers and conquer enemies.
The two stable isotopes of silver, silver-107 and silver-109, contribute to its average atomic mass in nearly equal amounts. As a result, pure silver is composed of about ninety percent of silver-107 and twenty-nine percent of silver-109.
Stable isotopes are characterized by the number of neutrons in their atomic nuclei. In contrast, radioactive isotopes are characterized by their decay products and their half-lives.
American Elements produces more than 250 stable metallic isotopes, which are used for biological and biomedical labeling, target materials and other applications. silver-109 is one of the most widely used of these isotopes.
Among the many redox processes that could affect the isotopic composition of an element, silver-109 is most susceptible to the Nuclear Field Shift effect, which can reduce ln b values by as much as -1 x 10-4 (two epsilon units) at 0 degC. This effect is strongest for Ag+ ions in hydrates, chloride complexes, sulfides, sulfates, Sb-As sulfosalts, carbonates, and As-ammines, but less so at higher temperatures.