Zinc is a metallic chemical element with atomic number 30. It is a first-row transition metal in group 12 of the periodic table. Zinc is chemically similar to magnesium because its ion is of similar size and its only common oxidation state is +2. Zinc is the 24th most abundant element in the Earth's crust and has five stable isotopes. The most exploited zinc ore is sphalerite, a zinc sulfide; the largest exploitable deposits are found in Australia, Canada and the United States. Brass, which is an alloy of copper and zinc, has been used since at least the 10th century BC. German chemist Andreas Sigismund Marggraf is normally given credit for discovering pure metallic zinc in a 1746 experiment. Work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by 1800. Corrosion-resistant zinc plating of steel is the major application for zinc. Other applications are in batteries and alloys, such as brass. Zinc is an essential mineral of "exceptional biologic and public health importance". Zinc deficiency affects about 2 billion people in the developing world and is associated with many diseases.
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_______________________________ Today's selected anniversaries:
1772:
A bloodless coup d'état led by Gustav III was completed with the adoption of a new Swedish Constitution. http://en.wikipedia.org/wiki/Gustav_III_of_Sweden
1831:
Nat Turner led a slave revolt in Southampton County, Virginia, USA, but it was suppressed about 48 hours later. http://en.wikipedia.org/wiki/Nat_Turner%27s_slave_rebellion
1959:
Under the terms of the Hawaii Admission Act and a subsequent plebiscite, the Territory of Hawaii was officially admitted as the 50th U.S. state. http://en.wikipedia.org/wiki/Hawaii_Admission_Act
1963:
The Army of the Republic of Vietnam Special Forces loyal to Ngo Dinh Nhu, brother of President Ngo Dinh Diem, raided and vandalised Buddhist pagodas across the country, arresting thousands and leaving an estimated hundreds dead. http://en.wikipedia.org/wiki/Xa_Loi_Pagoda_raids
1968:
The "Prague Spring", a period of political liberalization in Czechoslovakia, abruptly ended after http://en.wikipedia.org/wiki/Prague_Spring
_____________________________ Wiktionary's word of the day:
crux (n): 1. The basic, central, or essential point or feature. 2. The critical or transitional moment or issue, a turning point http://en.wiktionary.org/wiki/crux
___________________________ Wikiquote quote of the day:
A means can be justified only by its end. But the end in its turn needs to be justified. --Leon Trotsky http://en.wikiquote.org/wiki/Leon_Trotsky