Mercury
انجمن علمی زبان انگلیسی مدرسه راهنمایی تیزهوشان شهید بهشتی بروجرد

 

Discovery of Mercury

Dr. Doug Stewart

Mercury or quicksilver has been known since ancient times. We do not know who discovered it.

Mercury was known to the ancient Chinese, Egyptians and Hindus and has been found in Egyptian tombs dating back to about 1500 B.C.

In the fourth century B.C. we find Aristotle refers to mercury in writing as ‘hydro-argyros’ – which translates as liquid-silver or water-silver.

The Romans modified the Greek name slightly, referring to mercury as Hydragyrum, from which we get mercury’s modern chemical symbol Hg.

Our modern name for the element was provided by alchemists. Alchemists observed the element’s rapid, liquid flow, and likened it to the fastest moving planet, Mercury. (The planet had been named after the fast moving Roman messenger of the gods, Mercury.)

Alchemists believed mercury was the most important of all substances because it encompassed solid and liquid, earth and heaven, and life and death. They also believed it offered the path by which base metals could become gold and represented the quintessential property of fluidity. They were wrong, of course!

Chinese emperors used mercury to prolong their lives – although in all probability it had the opposite effect. (Despite the fact that mercury is now known to be highly toxic, some traditional Chinese medicines still appear to contain high levels of mercury.)

In 1759 Adam Braun and Mikhail Lomonosov working in St. Petersburg, Russia obtained solid mercury by freezing a mercury thermometer in a mixture of snow and concentrated nitric acid. This provided strong evidence that mercury had properties similar to other metals.

In 1772 and 1774, Swedish scientist Carl W. Scheele and English chemist Joseph Priestley heated mercury oxide and found it yielded a gas that made a candle burn five times faster than normal – they had discovered oxygen.

Priestley discovered several gases, such as nitrous oxide (laughing gas) because he collected them over a bath of mercury instead of the more usual water. Unlike water, the mercury did not dissolve the gases, leaving them available for discovery.

English chemist Humphry Davy used mercury in other discovery work. For example, Davy isolated calcium for the first time, using a mercury electrode to form an amalgam with the calcium



نظرات شما عزیزان:

نام :
آدرس ایمیل:
وب سایت/بلاگ :
متن پیام:
:) :( ;) :D
;)) :X :? :P
:* =(( :O };-
:B /:) =DD :S
-) :-(( :-| :-))
نظر خصوصی

 کد را وارد نمایید:

 

 

 

عکس شما

آپلود عکس دلخواه:









تاريخ : پنج شنبه 16 آذر 1391برچسب:,
ارسال توسط