Wikipedia:Today's featured article/August 21, 2009



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, in some respects, 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 two billion people in the developing world and is associated with many diseases. (more...)

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