Chemical Properties
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28-12-2018
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Chemical Properties
Silver also played a vital role in photography and consequently, medicine. The first camera-like apparatus was developed during the Middle Ages, but they had no way to make the captured images permanent. Then during the 19th century, the first permanent photos were developed using silver nitrate coated glass plates, which were used as negatives, and modern photography soon developed. However, this process is quickly becoming obsolete due to the emergence of digital photography.
The development of permanent photography catalyzed the development of modern medicine. As a result of permanent photography and the silver halides used in its development, William Conraad Roentgen was able to use radiation to create a picture of a person's skeleton, making it easier for doctors to diagnose their patients.
Even though coinage metals are known to be resistant to oxygen in air, silver will tarnish due to H2S(g)
2Ag(s)+H2S(g)→Ag2S(s)+H2(g)
Pure silver metal is the best conductor of heat and electricity. Pure silver would be too soft for jewelry and utensils so it is usually alloyed with at least one other metal. Sterling silver, for example, is usually about 93% silver and 7% other metals, mostly copper.
Silver can be found in high concentrations as argentite, Ag2S , but most is recovered in the refining processes of other metals such as copper. Most silver compounds are light sensitive and a lot of silver bromide and silver chloride are used by the photographic industry.
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