Zinc




 * Chemical series || Transition metals ||
 * Group, period, block || 12, 4, d ||
 * Appearance || Bluish pale gray ||
 * Electron configuration || [Ar] 3d10 4s2 ||
 * Electrons per shell || 2, 8, 18, 2 ||




 * It is the first element in group 12 of the periodic table. Zinc is a transition metal with a blueish-white color.
 * Zinc is a metallic chemical element and it makes up .0075% of the Earth's crust and is the 24th most abundant element in this World. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C. For a metal, zinc has relatively low melting (419.5 °C, 787.1 F) and boiling points (907 °C). Its melting point is the lowest of all the transition metals aside from mercury or cadmium. Above 210 °C, the metal becomes brittle again and can be pulverized by beating. It is a fair conductor of electricity.
 * The largest mine-able amounts of zinc are found in Australia, Asia, and the United States. If you burn zinc in air it can create a substance that is described as looking like white snow.
 * Five isotopes of zinc occur in nature (see below).
 * 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. In children it causes growth retardation, delayed sexual maturation, infection susceptibility, and diarrhea, contributing to the death of about 800,000 children worldwide per year. [|Enzymes] with a zinc atom in the [|reactive center] are widespread in biochemistry, such as [|alcohol dehydrogenase] in humans. Consumption of excess zinc can cause [|ataxia], [|lethargy] and [|copper deficiency].



Google Image

There are 21 known isotopes of Zinc. ** 5 are stable isotopes and 16 are unstable. ** **Notable Isotopes of Zinc**
 * //iso// || //NA// || //half-life// || //DM// || //DE (MeV)// || //DP// ||
 * 64Zn || 48.6% || Zn is stable with 34 neutrons. ||  ||   ||   ||
 * 65Zn || syn || 244.26 d || ε / Y || - / 1.1155 || 65Cu / - ||
 * 66Zn || 27.9% || Zn is stable with 36 neutrons. ||  ||   ||   ||
 * 67Zn || 4.1% || Zn is stable with 37 neutrons. ||  ||   ||   ||
 * 68Zn || 18.8% || Zn is stable with 38 neutrons. ||  ||   ||   ||
 * 69Zn || syn || 56.4 min || β- || 0.906 || 69Ga ||
 * 70Zn || 0.6% || Zn is stable with 40 neutrons. ||  ||   ||   ||

Zinc is blueish-white in color. Zinc is a transition metal.

__Zinc Found Critical Within the Brain to__ Improve Memory __and Cognition__(NaturalNews) Zinc is an __essential mineral__ known to improve skin tone, aid wound healing, fight cancer and shorten the length of the common cold. Researchers publishing in the journal //Neuron// now identify the crucial role this super-nutrient plays in support of memory formation and cognitive stability. Additionally, they have found that zinc may also play a part in controlling the devastating occurrence of epileptic seizures. For the first time, scientists have been able to watch zinc in action as the nutrient regulates communications between neurons and the hippocampus to improve memory and learning capabilities. Ensuring proper intake of zinc is an important step toward optimal brain function and may prevent cognitive decline as we age.

Researchers at Duke University Medical Center and chemists at the Massachusetts Institute of Technology collaborated to __study__ the effects of zinc on brain function. Scientists experimenting with mice used a chemical that binds with zinc to eliminate it from the brain of the test animals. They found that in the absence of the mineral, communications between neurons was significantly diminished and that zinc is vital for controlling the efficiency between nerve cells in the hippocampus.

For more than a half century, scientists have understood that high concentrations of zinc are deposited within nerve cells; called vesicles, they package the transmitters which enable the nerve cells to communicate. The highest concentrations of brain zinc are found among the neurons of the hippocampus that control the high functions of learning and memory.

**Symbol:** Zn **Atomic Number:** 30 **Atomic Mass:** 65.39 amu **Melting Point:** 419.58 °C (692.73 K, 787.24396 °F) **Boiling Point:** 907.0 °C (1180.15 K, 1664.6 °F) **Number of Protons/Electrons:** 30 **Number of Neutrons:** 35 **Classification:** Transition Metal **Crystal Structure:** Hexagonal **Density @ 293 K:** 7.133 g/cm3 **Color:** bluish

Atomic Structure

 * [[image:http://www.chemicalelements.com/bohr/b0030.gif width="277" height="275"]] ||  || **Number of Energy Levels:** 4
 * First Energy Level:****Second Energy Level:****Third Energy Level:****Fourth Energy Level:** ||

Isotopes

 * ** Isotope ** || ** Half Life ** ||
 * Zn-62 || 9.26 hours ||
 * Zn-63 || 38.5 minutes ||
 * Zn-64 || Stable ||
 * Zn-65 || 243.8 days ||
 * Zn-66 || Stable ||
 * Zn-67 || Stable ||
 * Zn-68 || Stable ||
 * Zn-69m || 13.76 hours ||
 * Zn-70 || Stable ||
 * Zn-72 || 46.5 hours ||

Facts
**Date of Discovery:** 1746 **Discoverer:** Andreas Marggraf **Name Origin:** From the German word //zin// (meaning tin) **Uses:** metal coating, rust protection, brass, bronze, nickel **Obtained From:** zinc blende, calamine

Zinc makes up about 75 ppm (0.0075%) of the Earth's crust, making it the 24th most abundant element. Soil contains 5–770 ppm of zinc with an average of 64 ppm. Seawater has only 30 ppb zinc and the atmosphere contains 0.1–4 µg/m3. The element is normally found in association with other base metals such as copper and lead in ores. Zinc is a chalcophile, meaning the element has a low affinity for oxides and prefers to bond with sulfides. Chalcophiles formed as the crust solidified under the reducing conditions of the early Earth's atmosphere. Sphalerite, which is a form of zinc sulfide, is the most heavily mined zinc-containing ore because its concentrate contains 60–62% zinc. Other minerals, from which zinc is extracted, include smithsonite (zinc carbonate), hemimorphite (zinc silicate), wurtzite (another zinc sulfide), and sometimes hydrozincite (basic zinc carbonate ). With the exception of wurtzite, all these other minerals were formed as a result of weathering processes on the primordial zinc sulfides.
 * Occurances**

Zinc was distinctly recognized as a metal under the designation of //Fasada// in the medical Lexicon ascribed to the Hindu king Madanapala and written about the year 1374. Smelting and extraction of impure zinc by reducing calamine with wool and other organic substances was accomplished in the 13th century in India. The Chinese did not learn of the technique until the 17th century. Alchemists burned zinc metal in air and collected the resulting zinc oxide on a condenser. Some alchemists called this zinc oxide //lana philosophica//, Latin for "philosopher's wool", because it collected in wooly tufts while others thought it looked like white snow and named it //nix album//. The name of the metal was probably first documented by Paracelsus, a Swiss-born German alchemist, who referred to the metal as "zincum" or "zinken" in his book //Liber Mineralium II//, in the 16th century. The word is probably derived from the German //zinke//, and supposedly meant "tooth-like, pointed or jagged" (metallic zinc crystals have a needle-like appearance). //Zink// could also imply "tin-like" because of its relation to German //zinn// meaning tin. Yet another possibility is that the word is derived from the Persian word سنگ //seng// meaning stone. The metal was also called Indian tin, tutanego, calamine, and spinter. German metallurgist Andreas Libavius received a quantity of what he called "calay" of Malabar from a cargo ship captured from the Portuguese in 1596. Libavius described the properties of the sample, which may have been zinc. Zinc was regularly imported to Europe from the Orient in the 17th and early 18th centuries, but was at times very expensive.
 * Naming and Early Studies**

Examples that zinc can be found in are air, soil, and water. Zinc is especially found in almost all foods. **Interesting Fact About Zinc:** Zinc is so essential that it's required by every cell in our bodies for everything from cell growth to immunity and even for our sense of taste and smell. Zinc is concentrated in the muscles, bones, kidneys, eyes, liver and also the prostate. Our bodies don't produce zinc so we must get it from our foods or a supplement. Zinc is a cofactor for just under 70 different enzymes.

Toxicity
Although zinc is an essential requirement for good health, excess zinc can be harmful. Excessive absorption of zinc suppresses copper and iron absorption.The free zinc ion in solution is highly toxic to plants, invertebrates, and even vertebrate fish. The Free Ion Activity Model is well-established in the literature, and shows that just [|micromolar] amounts of the free ion kills some organisms. A recent example showed 6 micromolar killing 93% of all // [|Daphnia] // in water. The free zinc ion is a powerful [|Lewis acid] up to the point of being [|corrosive]. Stomach acid contains [|hydrochloric acid], in which metallic zinc dissolves readily to give corrosive zinc chloride. Swallowing a post-1982 American one [|cent] piece (97.5% zinc) can cause damage to the stomach lining due to the high solubility of the zinc ion in the acidic stomach. There is evidence of induced [|copper deficiency] at low intakes of 100–300 mg Zn/day; a recent trial had higher hospitalizations for urinary complications compared to placebo among elderly men taking 80 mg/day. The [|USDA] [|RDA] is 11 and 8 mg Zn/day for men and women, respectively.Even lower levels, closer to the RDA, may interfere with the utilization of copper and iron or adversely affect cholesterol.Levels of zinc in excess of 500 ppm in soil interfere with the ability of plants to absorb other essential metals, such as iron and manganese. There is also a condition called the [|zinc shakes] or "zinc chills" that can be induced by the inhalation of freshly formed zinc oxide formed during the welding of [|galvanized] materials. Zinc is a common ingredient of [|denture] cream which may contain between 17 and 38mg of zinc per gram. There have been cases of disability or even death due to excessive use of these products. The U.S. [|Food and Drug Administration] (FDA) has stated that zinc damages nerve receptors in the nose, which can cause [|anosmia]. Reports of anosmia were also observed in the 1930s when zinc preparations were used in a failed attempt to prevent [|polio] infections. On June 16, 2009, the FDA said that consumers should stop using zinc-based intranasal cold products and ordered their removal from store shelves. The FDA said the loss of smell can be life-threatening because people with impaired smell cannot detect leaking gas or smoke and cannot tell if food has spoiled before they eat it. Recent research suggests that the topical antimicrobial zinc pyrithione is a potent [|heat shock] response inducer that may impair genomic integrity with induction of [|PARP] -dependent energy crisis in cultured human [|keratinocytes] and [|melanocytes].

Poisoning
In 1982, the [|United States Mint] began minting [|pennies] coated in copper but made primarily of zinc. With the new zinc pennies, there is the potential for zinc toxicosis, which can be fatal. One reported case of chronic ingestion of 425 pennies (over 1 kg of zinc) resulted in death due to gastrointestinal bacterial and fungal [|sepsis], while another patient, who ingested 12 grams of zinc, only showed [|lethargy] and [|ataxia] (gross lack of coordination of muscle movements). Several other cases have been reported of humans suffering zinc intoxication by the ingestion of zinc coins. Pennies and other small coins are sometimes ingested by dogs, resulting in the need for medical treatment to remove the foreign body. The zinc content of some coins can cause zinc toxicity, which is commonly fatal in dogs, where it causes a severe [|hemolytic anemia], and also liver or kidney damage; vomiting and diarrhea are possible symptoms.Zinc is highly toxic in [|parrots] and poisoning can often be fatal. [|[198]] The consumption of fruit juices stored in galvanized cans has resulted in mass parrot poisonings with zinc.

Dietary intake
   [|Foods & spices] containing zinc In the U.S., the [|Recommended Dietary Allowance] (RDA) is 8 mg/day for women and 11 mg/day for men. [|[168]] Median intake in the U.S. around 2000 was 9 mg/day for women and 14 mg/day in men. Oysters, lobster and red meats, especially [|beef], [|lamb] and [|liver] have some of the highest concentrations of zinc in food. <span style="background-color: #ffffff; color: #000000; display: block; font-family: sans-serif; text-align: left; text-decoration: none;">The concentration of zinc in plants varies based on levels of the element in soil. When there is adequate zinc in the soil, the food plants that contain the most zinc are wheat (germ and bran) and various seeds ( [|sesame], [|poppy] , [|alfalfa] , [|celery] , [|mustard] ). Zinc is also found in [|beans], [|nuts] , [|almonds] , [|whole grains] , [|pumpkin seeds] , [|sunflower seeds] and [|blackcurrant]. <span style="background-color: #ffffff; color: #000000; display: block; font-family: sans-serif; text-align: left; text-decoration: none;">Other sources include [|fortified food] and [|dietary supplements], which come in various forms. A 1998 review concluded that zinc oxide, one of the most common supplements in the United States, and zinc carbonate are nearly insoluble and poorly absorbed in the body.This review cited studies which found low plasma zinc concentrations after zinc oxide and zinc carbonate were consumed compared with those seen after consumption of zinc acetate and sulfate salts. However, harmful excessive supplementation is a problem among the relatively affluent, and should probably not exceed 20 mg/day in healthy people, although the U.S. National Research Council set a Tolerable Upper Intake of 40 mg/day. <span style="background-color: #ffffff; color: #000000; display: block; font-family: sans-serif; text-align: left; text-decoration: none;">For fortification, however, a 2003 review recommended zinc oxide in cereals as cheap, stable, and as easily absorbed as more expensive forms. A 2005 study found that various compounds of zinc, including oxide and sulfate, did not show statistically significant differences in absorption when added as fortificants to maize tortillas. A 1987 study found that zinc picolinate was better absorbed than zinc gluconate or zinc citrate.However, a study published in 2008 determined that zinc glycinate is the best absorbed of the four dietary supplement types available.

Deficiency
<span style="background-color: #ffffff; color: #000000; display: block; font-family: sans-serif; text-align: left; text-decoration: none;">Zinc deficiency is usually due to insufficient dietary intake, but can be associated with [|malabsorption], [|acrodermatitis enteropathica] , chronic liver disease, chronic renal disease, sickle cell disease, diabetes, malignancy, and other chronic illnesses. Symptoms of mild zinc deficiency are diverse. Clinical outcomes include depressed growth, diarrhea, impotence and delayed sexual maturation, [|alopecia], eye and skin lesions, impaired appetite, altered cognition, impaired host defense properties, defects in carbohydrate utilization, and reproductive teratogenesis.Mild zinc deficiency depresses immunity,although excessive zinc does also. Animals with a diet deficient in zinc require twice as much food in order to attain the same weight gain as animals given sufficient zinc. <span style="background-color: #ffffff; color: #000000; display: block; font-family: sans-serif; text-align: left; text-decoration: none;">Groups at risk for zinc deficiency include the elderly, and those with renal insufficiency. The zinc [|chelator] [|phytate], found in seeds and [|cereal] [|bran] , can contribute to zinc malabsorption. [|[] <span style="background-color: #ffffff; color: #000000; display: block; font-family: sans-serif; text-align: left; text-decoration: none;">Despite some concerns, western vegetarians and vegans have not been found to suffer from overt zinc deficiencies any more than meat-eaters. Major plant sources of zinc include cooked dried beans, sea vegetables, fortified cereals, soyfoods, nuts, peas, and seeds. However, phytates in many whole-grains and fiber in many foods may interfere with zinc absorption and marginal zinc intake has poorly understood effects. There is some evidence to suggest that more than the US RDA (15 mg) of zinc daily may be needed in those whose diet is high in phytates, such as some vegetarians. These considerations must be balanced against the fact that there is a paucity of adequate zinc [|biomarkers], and the most widely used indicator, plasma zinc, has poor [|sensitivity and specificity]. Diagnosing zinc deficiency is a persistent challenge. <span style="background-color: #ffffff; color: #000000; display: block; font-family: sans-serif; text-align: left; text-decoration: none;">Nearly two billion people in the developing world are deficient in zinc.In children it causes an increase in infection and diarrhea, contributing to the death of about 800,000 children worldwide per year. [|[1]] The World Health Organization advocates zinc supplementation for severe malnutrition and diarrhea. Zinc supplements help prevent disease and reduce mortality, especially among children with low birth weight or stunted growth.However, zinc supplements should not be administered alone, since many in the developing world have several deficiencies, and zinc interacts with other micronutrients. <span style="background-color: #ffffff; color: #000000; display: block; font-family: sans-serif; text-align: left; text-decoration: none;">Zinc deficiency is crop plants' most common micronutrient deficiency; it is particularly common in high-pH soils. Zinc-deficient [|soil] is [|cultivated] in the cropland of about half of Turkey and India, a third of China, and most of Western Australia, and substantial responses to zinc fertilization have been reported in these areas. Plants that grow in soils that are zinc-deficient are more susceptible to disease. Zinc is primarily added to the soil through the weathering of rocks, but humans have added zinc through fossil fuel combustion, mine waste, phosphate fertilizers, limestone, manure, sewage sludge, and particles from galvanized surfaces. Excess zinc is toxic to plants, although zinc toxicity is far less widespread.

Environmental impact
The production for sulfidic zinc ores produces large amounts of sulfur dioxide and cadmium vapor. Smelter slag and other residues of process also contain significant amounts of heavy metals. About 1.1 million tonnes of metallic zinc and 130 thousand tonnes of lead were mined and smelted in the Belgian towns of La Calamine and Plombières between 1806 and 1882. The dumps of the past mining operations leach significant amounts of zinc and cadmium, and, as a result, the sediments of the Geul River contain significant amounts of heavy metals. About two thousand years ago emissions of zinc from mining and smelting totaled 10 thousand tonnes a year. After increasing 10-fold from 1850, zinc emissions peaked at 3.4 million tonnes per year in the 1980s and declined to 2.7 million tonnes in the 1990s, although a 2005 study of the Arctic troposphere found that the concentrations there did not reflect the decline. Anthropogenic and natural emissions occur at a ratio of 20 to 1