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.
Read the rest of this article:
<http://en.wikipedia.org/wiki/Zinc>
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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>
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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>
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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>