1 янв 5000 г. до нашей эры - silver
Описание:
Silver is found in a native form very rarely as nuggets, but more usually combined with sulfur, arsenic, antimony, or chlorine and in various ores such as argentite. The ore is crushed, concentrated and then treated with sodium cyanide solution. Then the silver obtained is purified by the electrolytic process.
-discovered in the Stone age
The Stone Age was a prehistoric period during which stone was widely used to make weaponry and other tools. The period lasted roughly 3.4 million years and ended between 8700 BCE and 2000 BC.
silver uses:
-t is used for jewellery.
silver tableware, where appearance is important.
-Silver is used to make mirrors, as it is the best reflector of visible light known, although it does tarnish with time.
-It is also used in dental alloys
-electrical contacts and batteries
Добавлено на ленту времени:
Дата:
1 янв 5000 г. до нашей эры
Сейчас
~ 7029 г назад
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