Zinc is a chemical element with the symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a blue-silvery appearance when oxidation is removed. It is the first element in group 12 of the periodic table. In some respects, It is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size. It is the 24th most abundant element in Earth’s crust and has five stable isotopes. The most common Zn ore is sphalerite (Zn blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. It is refined by froth flotation of the ore, roasting, and final extraction using electricity
The element was probably named by the alchemist Paracelsus after the German word Zinke (prong, tooth). German chemist Andreas Sigismund Marggraf is credited with discovering pure metallic Zn in 1746. Work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by 1800. Corrosion-resistant zinc plating of iron (hot-dip galvanizing) is the major application for Zn. Other applications are in electrical batteries, small non-structural castings, and alloys such as brass. A variety of zinc compounds are commonly used, such as zinc carbonate and Zn gluconate, Zn chloride (in deodorants), zinc pyrithione (anti-dandruff shampoos), Zn sulfide (in luminescent paints), and dimethylzinc or diethylzinc in the organic laboratory.
Physical Characteristics of Zinc
- It is a bluish-white, lustrous, diamagnetic metal, though most common commercial grades of the metal have a dull finish. It is somewhat less dense than iron and has a hexagonal crystal structure.
- The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C. Above 210 °C, the metal becomes brittle again and can be pulverized by beating.
- It is a fair conductor of electricity. For a metal, Zn has relatively low melting (419.5 °C) and boiling points (907 °C). The melting point is the lowest of all the d-block metals aside from mercury and cadmium; for this, among other reasons, Zn, cadmium, and mercury are often not considered to be transition metals like the rest of the d-block metals.
- Many alloys contain Zn, including brass. Other metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium, and sodium.