“Catalyst of the Week”

47 palladium ← silver → cadmium Cu ↑ Ag ↓ Au Periodic Table - Extended Periodic Table

Silver is a chemical element with the chemical symbol Ag (Latin: argentum) and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal. Most silver is produced as a by-product of copper, gold, lead, and zinc refining.

Silver has been known since ancient times and has long been valued as a precious metal, used to make ornaments, jewelry, high-value tableware, utensils , and currency coins. Today, silver metal is used in electrical contacts and conductors, in mirrors and in catalysis of chemical reactions. Its compounds are used inphotographic film and dilute solutions of silver nitrate and other silver compounds are used as disinfectants. Although theantimicrobial uses of silver have largely been supplanted by the use of antibiotics, further research into its clinical potential is in progress. 

Catalyst Silver is probably the only catalyst available today to convert ethylene to ethylene oxide (later hydrolyzed to ethylene glycol, used for making polyesters)—a very important industrial reaction. Oxygen dissolves in silver relatively easily compared to other gases present in air. Attempts have been made to construct silver membranes of only a few monolayers thickness. Such a membrane could be used to filter pure oxygen from air and water.

Medicine

Silver ions and silver compounds show a toxic effect on some bacteria, viruses, algae and fungi, typical for heavy metals like lead or mercury, but without the high toxicity to humans that are normally associated with these other metals. Its germicidal effects kill many microbial organisms in vitro, but testing and standardization of silver products is difficult  recently there has been renewed interest in silver as a broad-spectrum antimicrobial. In particular, silver is being used with alginate, a naturally occurring biopolymer derived from seaweed, in a range of products designed to prevent infections as part of wound management procedures, particularly applicable to burn victims.

Electrolytically dissolved silver has been used as a water disinfecting agent., Colloidal silver is a liquid suspension of microscopic particles of silver. A colloid is technically defined as particles which remain suspended without forming an ionic, or dissolved solution. Currently, colloidal silver is marketed for internal use as an alternative medical remedy, though there is no scientific evidence of its effectiveness for any medical condition.Excessive use can result in argyria, a form of silver toxicity.

Food

In India and Pakistan, foods, especially sweets, can be found decorated with a thin layer of silver known as vark. Silver as a food additive is given the E number E174 and is classed as a food coloring. It is used solely for external decoration, such as on chocolate confectionery, in the covering of dragées and the decoration of sugar-coated flour confectionery. In Australia, it is banned as a food additive.

Clothing

Silver inhibits the growth of bacteria and fungi. It keeps odor to a minimum and reduces the risk of bacterial and fungal infection. In clothing, the combination of silver and moisture movement (wicking) may help to reduce the harmful effects of prolonged use in active and humid conditions

And the many other things 

Photography used in the form of silver nitrate and silver halides.

Mirrors which need superior reflectivity for visible light are made with silver as the reflecting material in a process called silvering, though common mirrors are backed with aluminium.

Many nations used silver as the basic unit of monetary value. The words for "silver" and "money" are the same in at least 14 languages. The name of the United Kingdom monetary unit "pound" reflects the fact that it originally represented the value of one troy pound of sterling silver.