Silver (47)

June 3^rd:
SILVER (47)

Silver is somewhat rare and expensive, although not as expensive as gold. Slag dumps in Asia Minor and on islands in the Aegean Sea indicate that man learned to separate silver from lead as early as 3000 B.C. Pure silver has a brilliant white metallic luster. It is a little harder than gold and is very ductile and malleable. Pure silver has the highest electric...al and thermal conductivity of all metals, and possesses the lowest contact resistance. Silver iodide, AgI, is (or was?) used for causing clouds to produce rain.

Silver is stable in pure air and water, but tarnishes when exposed to ozone, hydrogen sulfide, or air containing sulphur. It occurs in ores including argentite, lead, lead-zinc, copper and gold found in Mexico, Peru, and the USA.

•Name: Silver
•Symbol: Ag
•Atomic number: 47
•Atomic weight: 107.8682
•Standard state: solid at 298 K
•CAS Registry ID: 7440-22-4
•Group in periodic table: 11
•Group name: Coinage metal
•Period in periodic table: 5
•Block in periodic table: d-block
•Color: silver
•Classification: Metallic

Historical information

Silver was discovered by Known since ancient times at no data in not known. Origin of name is from the Anglo-Saxon word "siolfur" meaning "silver" (the origin of the symbol Ag comes from the Latin word "argentum" meaning "silver"). Silver has been known since ancient times. It is mentioned in Genesis. Slag dumps in Asia Minor and on islands in the Aegean Sea indicate that man learned to separate silver from lead as early as 3000 B.C.

Silver is one of the elements which has an alchemical symbol, alchemy is an ancient pursuit concerned with, for instance, the transformation of other metals into gold.

Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy. The symbol used by Dalton for silver is a circle with an upper case S in the middle.

Physical properties

•Melting point: 1234.93 [or 961.78 °C (1763.2 °F)] K
•Boiling point: 2435 [or 2162 °C (3924 °F)] K
•Density of solid: 10490 kg m-3

Orbital properties

•Ground state electron configuration: [Kr].4d10.5s1
•Shell structure: 2.8.18.18.1
•Term symbol: 2S1/2

Isolation

Silver is readily available commercially so it is not normally necessary to prepare silver in the laboratory. However the formation of silver metal may be demonstrated in a satisfying reaction in which copper metal is dipped into a solution of silver nitrate, AgNO3.

Cu(s) + 2 AgNO3 (aq) → Cu(NO3)2 + 2 Ag (s)

The result is formation of often attractive silver crystals and a blue-green solution of copper nitrate. Industrially, silver is usually a byproduct of processes whose main object is the extraction of another metal such as copper, lead, and zinc. So called "anode slimes" from the electrolytic purification of copper contain silver and a somewhat involved process is finished by electrolysis of a nitrate solution containing silver.