Zinc is a chemical element with the atomic number 30 in the periodic table. It’s the 24th most abundant element in Earth’s crust. As a member of the transition metals family of elements, zinc is a divalent chemical that forms numerous compounds with wide application in medicine and almost all industrial branches. Today, this non-ferrous base metal is the fourth most commonly used metal after iron, aluminum, and copper.
Being an important dietary nutrient, zinc participates in a vast number of vital metabolic and cellular processes in our body. The bioavailability of this mineral is extremely significant for the homeostatic processes of the human body. Zinc deficiency is considered to be one of the most common public health problems in the world. [Ref.: Zinc deficiency, infectious disease and mortality in the developing world. J Nutr 2003;133:1485S-9S. Prasad AS, Beck FW, Bao B, Snell D, Fitzgerald JT.]
Chemical and Physical Properties of Zinc
|Atomic weight||65.39 g.mol-1|
|Group||12 (Transition metals)|
|Color||A bluish-white and lustrous metal|
|Physical state||Solid at 20°C|
|Half-life||From more than 1.6 milliseconds to 244.26 days|
|Melting point||692.8°C, 787.149°F, 692.677 K|
|Boiling point||1184°C, 1665°F, 1180 K|
|Van der Waals radius||0.138 nm|
|Ionic radius||0.074 nm (+2)|
|Most characteristic isotope||64Zn|
|Electronic shell||[Ar] 3d10 4s2|
|The energy of the first ionization||904.5 kJ.mol-1|
|The energy of the second ionization||1723 kJ.mol-1|
|Uses||Used to coat other metals (galvanizing) to protect them from rusting. Also in alloys such as brass, bronze, nickel. Also in solder, cosmetics, and pigments.|
|Description||Soft, blue-white metal.|
|Covalent Radius||1.25 Å|
|Atomic Radius||1.53 Å|
|Atomic Volume||09.2 cm³/mol|
|Name Origin||German: zink (German for tin).|
With the periodic table symbol Zn, atomic number 30, atomic mass of 65.38 g.mol-1, and electron configuration [Ar] 3d104s2, zinc is a brittle, silvery-white metal at room temperature. It reaches its boiling point at 907°C, 1665°F, 1180K, while the melting point is achieved at 419.527°C, 787.149°F, 692.677K. When exposed to temperatures that range between 230F (110°C) and 300F (150°C), zinc metal becomes more malleable and ductile. In addition, this member of the transition metals family of elements has an electronegativity of 1.6 according to Pauling, whereas the atomic radius according to van der Waals is 0.138 nm.
Zinc has a hexagonal packed structure and shares similar chemical properties with magnesium. It’s a moderately strong conductor of both heat and electricity. When exposed to air, this transition metal reacts with carbon dioxide and forms a layer of zinc carbonate that protects the metal and prevents the formation of additional reactions with water or air. Accordingly, zinc possesses strong anti-corrosive properties.
How Was Zinc Discovered?
Zinc metal has been around since ancient times. The earliest archaeological evidence points to Switzerland, China, Greece, Cyprus, and Palestine as the first locations where zinc had been used. According to a research paper in archeology, this chemical element was mostly used in copper for making brass. The first uncovered brass artifacts originate from Babylonia and Assyria (3000 B.C.), and Palestine (1400-1000 B.C.).
To continue with, the first scientifically supported evidence of zinc smelting identifies India on the map of the world as the place where the first zinc smelting in the history of civilization took place during the period from 1100-1500. In the city of Zawar, Rajasthan, the first quantities of zinc were obtained by reducing calamine (zinc carbonate, ZnCO3) with wool.
The Discovery of Andreas Marggraf
In contemporary times, the German chemist Andreas Sigismund Marggraf (1709-1782) is considered to be the discoverer of zinc as a chemical element because he was the first scientist to recognize the substance as a new individual chemical.
This Berlin-born pioneer of analytical chemistry succeeded in isolating the pure, elemental form of zinc in 1746 by heating a mixture of calamine (a mineral ore of zinc) and carbon. Marggraf was also credited as the first chemist to observe the chemical and physical properties of the element 30 and provide scientific evidence for it.
The Contribution of Luigi Galvani and Alessandro Volta
The Italian physician and physicist Luigi Galvani (the pioneer of bioelectromagnetics) together with his colleague Alessandro Volta (the pioneer of electricity) employed all of their knowledge and experience for further analysis of the new chemical element.
By 1800, these two great Italian scientists succeeded in determining the electrochemical properties of zinc, which provided the element’s ability to form a corrosion-resistant coating for iron and steel. Today, it’s considered to be one of the most exploited properties of zinc.
How Did Zinc Get Its Name?
This chemical element got its name after the old German word ‘zinke’, which means ‘pointed’. This word directly refers to the sharply pointed crystals of zinc that form after the process of smelting.
Where Can You Find Zinc?
The elemental zinc metal can be found in various minerals, such as hydrozincite, calamine, sphalerite, franklinite, wurtzite, hemimorphite, and smithsonite. Among them, calamine (zinc silicate), sphalerite (zinc sulphide, or blende), and smithsonite (zinc carbonate) are the most frequently mined mineral ores from which zinc can be obtained in a relatively easy process. One of the oldest and easiest methods of producing zinc from the ores is by reducing calamine with carbon or charcoal.
- Zinc chloride hydroxide monohydrate
The most significant zinc ore deposits can be found in mines located in the United States, Iran, Canada, and Australia. Over 90% of the zinc supplies in the world are obtained from zinc blende (ZnS).
Zinc in Everyday Life
This chemical element has a vast variety of everyday uses. Zinc and its compounds have been widely applied as one of the main components in some medical preparations and procedures, in many industrial processes, as well as in a large palette of household and gardening products:
- Zinc containing products have been widely used in skin treatments, as a remedy for infections, acne, skin ulcers, rashes, and similar skin disorders;
- The cobalt green (or zinc green) pigment is produced by exposing a cobalt and zinc oxide mixture to high temperatures. After the heating of the compound, the resulting substance is washed and ground into this bright, bluish-green pigment.
- Zinc oxide is the industrially most important zinc compound. It’s widely used in chemicals, paints, enamels, fabrics, plastics, lubricants, glass and rayon manufacturing, rubber, floor coverings, etc. Also, zinc oxide is one of the most important ingredients in the sun-blocking lotions that protect our skin against UV rays;
- This chemical (Zn) is also used in the production of some denture adhesive creams, as well as in die-casting in the automobile industry;
- The alloy of copper and zinc is used for making brass;
- Zinc chloride is commonly used in soldering and welding, for fireproofing, as a wood preservative, and as a cauterizing agent in medicine. Furthermore, this zinc compound is used in printing and dyeing textiles, in dry cell batteries as an electrolyte, in the process of vulcanization of rubber, as a corrosion inhibitor in water treatment, etc.;
- Zinc cyanide has a wide application in the production of insecticides, electroplating, gold extraction, as well as in the process of removing ammonia from producer gas;
- Apart from being used in the manufacturing of zinc salts, porcelains, pottery, and rubber, zinc carbonate has also been used in the production of cosmetics and face lotions;
- Zinc fluoride’s main use is in the manufacturing of phosphors for fluorescent lights, as an agent in porcelain’s glazes and enamels, as well as a termite repellent;
- Zinc sulfate is often applied as a reagent in analytical chemistry, in the manufacture of skin fresheners, fertilizers, and herbicides, and as a sewage agent against animal pathogenic bacteria. However, its most popular use is as a supplement for patients, animals, and plants with zinc deficiency;
- Zinc sulfide’s most notable application is as a phosphor in TV and X-ray screens, in the luminous dials of watches, as a semiconductor, a photoconductor for solar cells, as well as a pigment in paper, paints, oil cloths, leather, and linoleum.
Zinc and Health
Zinc is the most abundant trace mineral in the human body right after iron. It supports the proper functioning of over 300 enzymes needed for performing some of the most vital functions in our body. Some of the benefits of zinc as one of the essential trace elements include the following instances:
- It contributes to a healthy cell division;
- It’s a vital component of the DNA polymerase complex enzymes which are essential for DNA replication;
- It’s one of the most vital participants in the production of DNA and protein synthesis;
- It supports the improvement of the growth and development in children during pregnancy, childhood, and adolescence;
- It activates the T lymphocytes (T cells that are responsible for determining the specificity of an immune response to antigens);
- It supports the immune system of our body;
- It supports faster healing of wounds;
- It contributes to the vitality of the skin;
- It prevents age-related macular degeneration;
- It aids digestion and contributes to the overall health of the gastrointestinal system;
- It regulates the metabolic processes;
- It plays a significant role in the health of the nerves;
- It regulates and controls our sense of taste and smell.
What Is Zinc Deficiency?
Hypozincemia, or zinc deficiency, occurs due to various medical conditions that deplete our body of this essential mineral. Most often, malnutrition, low intake of zinc, or malabsorption of the element are the number one reason that triggers lack of zinc in the body’s systems which further leads to the dysfunction of a large number of metabolic and cellular processes. [Ref.: Prasad AS (March 2013). “Discovery of human zinc deficiency: its impact on human health and disease”.]
Zinc deficiency can also be caused by the following risk factors and health issues:
- Renal disease;
- Chronic liver disease;
- Sickle cell anemia;
- Various types of cancer and tumor growth;
- A diet high in phytates;
- A vegetarian diet based on food low in zinc content;
- Ulcerative colitis;
- Iron supplements intake that may interfere with the zinc absorption;
- Obesity treating surgery.
What Are the Symptoms of Zinc Deficiency?
The common effects associated with low levels of zinc in our body include:
- Hair loss;
- Weight loss;
- Memory loss;
- Iron deficiency;
- Loss of appetite;
- Vision problems;
- Copper deficiency;
- Growth retardation;
- Hormonal disbalance;
- Delayed wound healing;
- Skin rash around the mouth;
- Frequent asthma exacerbations;
- Memory and concentration problems;
- Lowered testosterone production in men (hypogonadism);
- Frequent flu-like symptoms, or symptoms resembling the common cold.
The aforementioned symptoms also typically occur with some other mineral deficiencies, which makes zinc deficiency difficult to be detected immediately. The assessment of the total serum zinc levels test is the best way for determining both the zinc concentration in our body, as well as the adequate zinc intake level for each individual.
A deficiency of this essential trace element in children causes the rare congenital condition referred to as acrodermatitis enteropathica. It is a fatal condition that occurs in three main forms:
- Peri-acral and periorificial dermatitis.
The milder forms in which this disease may occur include:
- Thermal burn;
- Candida infection;
- Seborrhoeic dermatitis;
- Linear IgA bullous disease.
All forms of acrodermatitis enteropathica (AE) result either from a dysfunctional zinc metabolism that manifests as an inability of the body to absorb zinc from the intestine, or defective genes, mutation of the transporter protein, inadequate zinc intake, excessive urinary loss of zinc, extensive surgery, chronic alcohol consumption, cirrhosis, pancreatic disease, intestinal bypass surgery, anorexia nervosa, zinc-deficient breast milk, or cystic fibrosis as some of the risk factors that lead to acrodermatitis enteropathica.
The patients affected by this genetically inherited or acquired disorder experience some of these symptoms:
- A periorificial rash (i.e. around the mouth and on the cheeks);
- Mouth ulcers;
- Impaired wound healing;
- Secondary infection with Candida albicans or Staphylococcus aureus;
- Loss of hair, eyebrows, and eyelashes;
- Loss of appetite;
- Growth failure in untreated children;
- Irritability (expressed with constant crying in children);
- Emotional disturbances;
- Bullae, pustules, erosions, or hyperkeratotic areas may occur on the face, elbows, knees, fingers, or toes.
Food Sources Rich in Zinc
Since our body doesn’t produce this micronutrient, the best way to supply it is via food high in zinc or zinc supplements. Zinc’s bioavailability is the greatest in meat and seafood, but this mineral can also be found in:
- Veal Liver;
- Whole Grains;
- Hemp Seeds;
- Unsweetened Baking Chocolate;
- Pumpkin Seeds;
- Baked Beans;
- Breakfast Cereals;
- Unsweetened Cocoa Powder;
- Chicken Hearts;
- Lamb Meat;
- Wild Rice;
- Cashew Nuts;
- Chia Seeds;
There are many benefits of including zinc in daily nutrition. To begin with, zinc decreases the risk of developing many serious diseases by fighting oxidative stress. Furthermore, this mineral supports healthy eyesight by reducing inflammation and by converting vitamin A into its active form.
Provided a person has difficulty with absorbing zinc from foods due to digestive disorders or very poor gut health, supplemental zinc might be a solution to a regular intake of this micronutrient. Also, this vitally important trace element cannot be produced or stored by our body in any specific tissue. Therefore, dietary zinc supplementation sometimes is a necessity for the improvement of the zinc status. Oral zinc supplements can be taken in a form of a lozenge, tablet, capsule, or syrup.
According to a study published by the US National Library of Health and the Health Institutes, dietary zinc intake has beneficial effects on overall health. The authors of this systematic review claim that zinc lozenges in the form of zinc sulfate, zinc acetate, and zinc gluconate are an effective treatment in cases of common cold and flu.
Namely, by alleviating the cold symptoms, they can shorten the common cold duration by 33 percent. Some clinical trials also show that zinc supplements are great boosters of the immune response of our body. On the other hand, if oral zinc is taken in high doses for a longer period, it may result in copper deficiency and neurological problems.
A meta-analysis published by the Cochrane Library also points out evidence that zinc supplementation as an addition to antibiotics in the clinical treatment of pneumonia did not provide a statistically significant effect on time‐to‐recovery. On the other hand, this Cochrane review also shows that preventive zinc supplementation did lower the risk of infectious diseases in children, particularly from pneumonia. [Ref.: Cochrane Database Syst Rev. 2016 Dec 4;12:CD005978. R3 Wang L, Song Y.]
As stated by a study published by The National Eye Institute, the use of zinc together with high doses of vitamin C, vitamin E, and beta carotene, contributes to a lowered risk of vision loss and age-related macular degeneration. This eye disease is considered to be the leading cause of visual impairment and blindness in aging Americans.
Dietary zinc is typically administered to protect the individual against an excessive loss of this mineral due to various medical conditions. As specified by the Office of Dietary Supplements (ODS), the table of daily recommended dietary allowance (RDA) of zinc is developed by the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies.
This table points out that the RDAs for male adults amounts to 11 mg of zinc, while the dietary reference intake (DRIs) for women is 8 mg a day. However, due to their specific condition and increased need for minerals, pregnant and lactating women need about 12 mg of zinc a day. Depending on the age, children’s needs of this trace element vary between 2 and 9 milligrams of daily intake.
In Which Cases Are Zinc Supplements Administered?
Zinc supplements are typically used in the therapy of some specific health conditions and diseases, including:
- Anorexia nervosa;
- Peptic ulcers;
- Hansen’s disease;
- Down syndrome;
- Alzheimer’s disease;
- Crohn’s disease;
- Serious head injuries;
- Attention deficit-hyperactivity disorder.
Important: Please note that this zinc fact sheet is for educational and informative purposes only. According to the National Institute of Health (NIH), many other drugs may interact with zinc, including other supplements, antacids, prescription, and over-the-counter medicines.
In addition, fluoroquinolone antibiotics (ciprofloxacin), tetracycline antibiotics (doxycycline, labeled as Vibramycin), Penicillamine (used in the treatment of rheumatoid arthritis), Thiazide diuretics drugs, some laxatives, antacids (such as calcium carbonate), diuretics, vitamin K, some trace minerals (iron, copper, manganese, molybdenum, boron, chromium), other mineral supplements, multivitamins, and chelating agents may interfere with the zinc absorption in the body and produce many side effects if taken simultaneously.
For this reason, we would hereby like to strongly recommend you seek medical advice from a qualified healthcare provider or dietitian before treating any health issues by adding any of the zinc supplements to your diet.
What Does Too Much Zinc Do to Our Body?
Excess zinc absorption in our body can be as dangerous as zinc deficiency. Namely, when the intake of this micronutrient is larger than the daily recommended amounts, accumulation of large amounts of zinc in the body may result in zinc toxicity. These dangerously high levels of zinc contribute to a decreased immune function, change in taste, copper deficiency, or low levels of the ‘good cholesterol’, i.e. high-density lipoprotein (HDL).
What are the Signs and Symptoms of Zinc Toxicity?
As a result of the acute zinc toxicity, the following symptoms may be experienced by the affected individual:
- Excess sweating;
- Weakness and fatigue;
- Soreness of the muscles;
- Chest pain;
- Severe bouts of cough;
- Difficulty breathing and swallowing;
- Abdominal cramps;
How Dangerous Is Zinc?
Breathing in too much zinc through metallurgic dust or fumes may lead to metal fume fever. This is typically an occupational disease that results from overexposure to this chemical element. When the metal or dust particles and fumes enter the respiratory pathway, they trigger the metal fume fever which lasts not more than 48 hours.
Environmental Effects of Zinc
The pure, elemental form of zinc naturally occurs in air, surface waters, drinking water supplies, soil, and some foods. However, this transition metal mainly enters the environment through industrial processes, mining, mineral processing, and wastes. The mining and processing of sulfidic zinc ores produce large amounts of sulfur dioxide (SO2), which is one of the main air pollutants that often forms acid rain.
Acid Rain and Zinc
When the atmospheric precipitation (rain, snow, frost, fog, hail, or mist) contains more acids than normal, it’s referred to as acid rain. It combines both the wet and dry harmful deposits of nitric and sulfuric acids released in the atmosphere via natural and man-made toxic emissions.
The environmental acidic precipitations are especially harmful to the plants, wildlife, the humans, but for the infrastructure and our homes, too. Namely, when the metal constructions are exposed to acid precipitation, they corrode, discolor, and degrade, which destroys the construction. Acid rains also contaminate both the soil and surface waters.
Isotopes of Zinc
Zinc-30 is the naturally occurring form of element 30. It’s made up of five stable isotopes: 64Zn, 66Zn, 67Zn, 68Zn, and 70Zn. Among them, zinc-64 is the most abundant form of zinc, occurring in nature with 48.6% of abundance.
There are a total of 30 isotopes of zinc with atomic mass ranging from zinc-54 to zinc-83, as well as 10 metastable states of its atomic nucleus. Out of all zinc forms, the 65Zn isotope takes 244.26 days to decay into another form, which makes it the longest living form of this chemical element.
|Z||N||Isotopic mass (Da)
[n 2][n 3]
[n 7][n 4]
|Natural abundance (mole fraction)|
|Excitation energy||Normal proportion||Range of variation|
|55Zn||30||25||54.98398(27)#||20# ms [>1.6 μs]||2p||53Ni||5/2−#|
|57Zn||30||27||56.96479(11)#||38(4) ms||β+, p (65%)||56Ni||7/2−#|
|58Zn||30||28||57.95459(5)||84(9) ms||β+, p (60%)||57Ni||0+|
|59Zn||30||29||58.94926(4)||182.0(18) ms||β+ (99%)||59Cu||3/2−|
|β+, p (1%)||58Ni|
|60Zn[n 8]||30||30||59.941827(11)||2.38(5) min||β+||60Cu||0+|
|64Zn||30||34||63.9291422(7)||Observationally Stable[n 9]||0+||0.4917(75)|
|70Zn||30||40||69.9253193(21)||Observationally Stable[n 10]||0+||0.0061(10)|
|79Zn||30||49||78.94265(28)#||0.995(19) s||β− (98.7%)||79Ga||(9/2+)|
|β−, n (1.3%)||78Ga|
|80Zn||30||50||79.94434(18)||545(16) ms||β− (99%)||80Ga||0+|
|β−, n (1%)||79Ga|
|81Zn||30||51||80.95048(32)#||290(50) ms||β− (92.5%)||81Ga||5/2+#|
|β−, n (7.5%)||80Ga|
|82Zn||30||52||81.95442(54)#||100# ms [>300 ns]||β−||82Ga||0+|
|83Zn||30||53||82.96103(54)#||80# ms [>300 ns]||5/2+#|
List of Zinc Compounds
This non-ferrous base metal forms numerous compounds with other chemical elements, most often with nickel, cobalt, copper, magnesium, tin, iron, tellurium, vanadium, silicon, silver, gold, lead, and bismuth. Both the physical and chemical properties among the compounds of zinc vary greatly. They each have a specific set of chemical properties, which makes this chemical element suitable for wide application in a vast range of industrial branches and spheres of living.
The list of most common zinc compounds comprises the following chemical combinations:
- Zinc acetate
- Zinc ammonium chloride
- Zinc antimonide
- Zinc arsenide
- Zinc azide
- Zinc bis(dimethyldithiocarbamate)
- Zinc borate
- Brilliant cresyl blue
- Zinc bromide
- Cadmium zinc telluride
- Zinc chlorate
- Zinc chloride
- Zinc chromate
- Cobalt green
- Zinc cyanide
- Zinc dithiophosphate
- Zinc ferrite
- Zinc fluoride
- Zinc gluconate
- Zinc hydride
- Zinc hydroxide
- Zinc iodide
- Jones reductor
- Zinc L-aspartate
- Zinc L-carnosine
- Mercury zinc telluride
- Zinc molybdate
- Zinc nitrate
- Zinc nitride
- Depleted zinc oxide
- Zinc oxide
- Zinc oxide eugenol
- Zinc oxide nanoparticle
- Zinc peroxide
- Zinc phosphate
- Zinc diphosphide
- Zinc phosphide
- Zinc picolinate
- Zinc proteinate
- Zinc pyrophosphate
- Zinc ricinoleate
- Zinc selenide
- Sodium zincate
- Zinc stearate
- Zinc sulfate
- Zinc cadmium sulfide
- Zinc sulfide
- Zinc telluride
- Zinc titanate
- Zinc triflate
- Uranyl zinc acetate
- Zinc cadmium phosphide arsenide
- Zinc pyrithione
5 Interesting Facts and Explanations
- Luigi Galvani (1737-1798) is an Italian physician, physicist, and pioneer of bioelectromagnetics is credited as a discoverer of animal electricity. In the world of science, Galvani is also known for conducting his electric current experiments on frogs’ legs, together with his fellow colleague, Alessandro Volta.
- Alessandro Giuseppe Antonio Anastasio Volta (1745-1827) is an Italian physicist and pioneer of electricity who invented the electric battery labeled as the ‘Voltaic pile’ in 1800. Volta’s electric battery consisted of a copper electrode and a zinc electrode, and sulfuric acid mixed with water or a form of saltwater brine as an electrolyte.
- As an essential trace mineral, zinc is mostly absorbed in the jejunum and duodenum of the human body.
- Prolonged use of a zinc-containing nasal spray and gels used in the treatment of the common cold may lead to permanent loss of the sense of smell, according to the FDA.
- American pennies are typically made of zinc in combination with other elements, such as copper, bronze, nickel, and tin.