Srebra

Srebra, in English silver, is a chemical element with the symbol Ag and atomic number 47. It is a transition metal in group 11 and period 5, known for its bright lustrous appearance, malleability, and high electrical and thermal conductivity. Silver has the highest electrical conductivity of any element and the highest thermal conductivity of any metal. It is relatively unreactive but tarnishes when exposed to air containing sulfur compounds, forming silver sulfide.

Occurrence and production: Silver occurs both as native metal and in various minerals, notably argentite (Ag2S) and chlorargyrite (AgCl). It is produced primarily as a byproduct of mining for copper, lead, and zinc ores; major producers include Mexico, Peru, China, Russia, and Australia. Refining is performed by smelting and electrolytic refinement; recycling of scrap silver is economically important.

Applications: Silver has long been used in jewelry, coins, tableware, and photography due to its luster and malleability, but its major modern uses include electronics and photovoltaic cells, where its high conductivity improves performance. Silver compounds are used in catalysis, antimicrobial coatings, and medical instruments, and silver halides are central to traditional photography. Its reflectivity also makes it valuable for mirrors and optics.

Isotopes and chemistry: Silver has two stable isotopes, 107Ag and 109Ag, with several radioactive isotopes of shorter half-lives. In chemistry, silver forms a variety of compounds, including halides and cyanides, and dissolves in nitric acid to yield silver nitrate.