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124-478: 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 shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table . In some respects, zinc is chemically similar to magnesium : both elements exhibit only one normal oxidation state (+2), and the Zn and Mg ions are of similar size. Zinc

248-408: A condenser . Some alchemists called this zinc oxide lana philosophica , Latin for "philosopher's wool", because it collected in wooly tufts, whereas 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

372-738: A pure element . In chemistry, a pure element means a substance whose atoms all (or in practice almost all) have the same atomic number, or number of protons . Nuclear scientists, however, define a pure element as one that consists of only one isotope. For example, a copper wire is 99.99% chemically pure if 99.99% of its atoms are copper, with 29 protons each. However it is not isotopically pure since ordinary copper consists of two stable isotopes, 69% Cu and 31% Cu, with different numbers of neutrons. However, pure gold would be both chemically and isotopically pure, since ordinary gold consists only of one isotope, Au. Atoms of chemically pure elements may bond to each other chemically in more than one way, allowing

496-420: A radioisotope of zinc with a mass number lower than 66 is electron capture . The decay product resulting from electron capture is an isotope of copper. The most common decay mode of a radioisotope of zinc with mass number higher than 66 is beta decay (β), which produces an isotope of gallium . Zinc has an electron configuration of [Ar]3d4s and is a member of the group 12 of the periodic table . It

620-549: A considerable amount of time. (See element naming controversy ). Precursors of such controversies involved the nationalistic namings of elements in the late 19th century. For example, lutetium was named in reference to Paris, France. The Germans were reluctant to relinquish naming rights to the French, often calling it cassiopeium . Similarly, the British discoverer of niobium originally named it columbium , in reference to

744-477: A different element in nuclear reactions , which change an atom's atomic number. Historically, the term "chemical element" meant a substance that cannot be broken down into constituent substances by chemical reactions, and for most practical purposes this definition still has validity. There was some controversy in the 1920s over whether isotopes deserved to be recognized as separate elements if they could be separated by chemical means. The term "(chemical) element"

868-652: A few decay products, to have been differentiated from other elements. Most recently, the synthesis of element 118 (since named oganesson ) was reported in October 2006, and the synthesis of element 117 ( tennessine ) was reported in April 2010. Of these 118 elements, 94 occur naturally on Earth. Six of these occur in extreme trace quantities: technetium , atomic number 43; promethium , number 61; astatine , number 85; francium , number 87; neptunium , number 93; and plutonium , number 94. These 94 elements have been detected in

992-529: A few elements, such as silver and gold , are found uncombined as relatively pure native element minerals . Nearly all other naturally occurring elements occur in the Earth as compounds or mixtures. Air is mostly a mixture of molecular nitrogen and oxygen , though it does contain compounds including carbon dioxide and water , as well as atomic argon , a noble gas which is chemically inert and therefore does not undergo chemical reactions. The history of

1116-631: A half-life of 243.66 days, is the least active radioisotope, followed by Zn with a half-life of 46.5 hours. Zinc has 10 nuclear isomers , of which Zn has the longest half-life, 13.76 h. The superscript m indicates a metastable isotope. The nucleus of a metastable isotope is in an excited state and will return to the ground state by emitting a photon in the form of a gamma ray . Zn has three excited metastable states and Zn has two. The isotopes Zn , Zn , Zn and Zn each have only one excited metastable state. The most common decay mode of

1240-512: A metal which, when oxidized, produces pushpanjan , thought to be zinc oxide. Zinc mines at Zawar, near Udaipur in India, have been active since the Mauryan period ( c.  322 and 187 BCE). The smelting of metallic zinc here, however, appears to have begun around the 12th century AD. One estimate is that this location produced an estimated million tonnes of metallic zinc and zinc oxide from

1364-415: A metal–carbon sigma bond . Cobalticyanide paper (Rinnmann's test for Zn) can be used as a chemical indicator for zinc. 4 g of K 3 Co(CN) 6 and 1 g of KClO 3 is dissolved on 100 ml of water. Paper is dipped in the solution and dried at 100 °C. One drop of the sample is dropped onto the dry paper and heated. A green disc indicates the presence of zinc. Various isolated examples of

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1488-670: A paper separator to act as what is known as a salt bridge . Heavy-duty types use a paste primarily composed of zinc chloride (ZnCl 2 ). Zinc–carbon batteries were the first commercial dry batteries, developed from the technology of the wet Leclanché cell . They made flashlights and other portable devices possible, because the battery provided a higher energy density at a lower cost than previously available cells. They are still useful in low-drain or intermittent-use devices such as remote controls , flashlights, clocks or transistor radios . Zinc–carbon dry cells are single-use primary cells . Zinc-carbon batteries today have been overtaken by

1612-500: A pressure of 1 bar and a given temperature (typically at 298.15K). However, for phosphorus, the reference state is white phosphorus even though it is not the most stable allotrope, and the reference state for carbon is graphite, because the structure of graphite is more stable than that of the other allotropes. In thermochemistry , an element is defined to have an enthalpy of formation of zero in its reference state. Several kinds of descriptive categorizations can be applied broadly to

1736-483: A pressure of one atmosphere, are commonly used in characterizing the various elements. While known for most elements, either or both of these measurements is still undetermined for some of the radioactive elements available in only tiny quantities. Since helium remains a liquid even at absolute zero at atmospheric pressure, it has only a boiling point, and not a melting point, in conventional presentations. The density at selected standard temperature and pressure (STP)

1860-507: A process in 1758 for calcining zinc sulfide into an oxide usable in the retort process. Prior to this, only calamine could be used to produce zinc. In 1798, Johann Christian Ruberg improved on the smelting process by building the first horizontal retort smelter. Jean-Jacques Daniel Dony built a different kind of horizontal zinc smelter in Belgium that processed even more zinc. Italian doctor Luigi Galvani discovered in 1780 that connecting

1984-590: A quantity of what he called "calay" (from the Malay or Hindi word for tin) originating from Malabar off a cargo ship captured from the Portuguese in the year 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. Metallic zinc was isolated in India by 1300 AD. Before it

2108-456: A small group, (the metalloids ), having intermediate properties and often behaving as semiconductors . A more refined classification is often shown in colored presentations of the periodic table. This system restricts the terms "metal" and "nonmetal" to only certain of the more broadly defined metals and nonmetals, adding additional terms for certain sets of the more broadly viewed metals and nonmetals. The version of this classification used in

2232-474: A whole number. For example, the relative atomic mass of chlorine is 35.453 u, which differs greatly from a whole number as it is an average of about 76% chlorine-35 and 24% chlorine-37. Whenever a relative atomic mass value differs by more than ~1% from a whole number, it is due to this averaging effect, as significant amounts of more than one isotope are naturally present in a sample of that element. Chemists and nuclear scientists have different definitions of

2356-493: A zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. Consumption of excess zinc may cause ataxia , lethargy , and copper deficiency . In marine biomes, notably within polar regions, a deficit of zinc can compromise the vitality of primary algal communities, potentially destabilizing the intricate marine trophic structures and consequently impacting biodiversity. Brass , an alloy of copper and zinc in various proportions,

2480-404: Is 10 (for tin , element 50). The mass number of an element, A , is the number of nucleons (protons and neutrons) in the atomic nucleus. Different isotopes of a given element are distinguished by their mass number, which is written as a superscript on the left hand side of the chemical symbol (e.g., U). The mass number is always an integer and has units of "nucleons". Thus, magnesium-24 (24

2604-402: Is a chalcophile , meaning the element is more likely to be found in minerals together with sulfur and other heavy chalcogens , rather than with the light chalcogen oxygen or with non-chalcogen electronegative elements such as the halogens . Sulfides formed as the crust solidified under the reducing conditions of the early Earth's atmosphere. Sphalerite , which is a form of zinc sulfide,

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2728-606: Is a mixture of C (about 98.9%), C (about 1.1%) and about 1 atom per trillion of C. Most (54 of 94) naturally occurring elements have more than one stable isotope. Except for the isotopes of hydrogen (which differ greatly from each other in relative mass—enough to cause chemical effects), the isotopes of a given element are chemically nearly indistinguishable. All elements have radioactive isotopes (radioisotopes); most of these radioisotopes do not occur naturally. Radioisotopes typically decay into other elements via alpha decay , beta decay , or inverse beta decay ; some isotopes of

2852-406: Is a dimensionless number equal to the atomic mass divided by the atomic mass constant , which equals 1 Da. In general, the mass number of a given nuclide differs in value slightly from its relative atomic mass, since the mass of each proton and neutron is not exactly 1 Da; since the electrons contribute a lesser share to the atomic mass as neutron number exceeds proton number; and because of

2976-583: Is a moderately reactive metal and strong reducing agent . The surface of the pure metal tarnishes quickly, eventually forming a protective passivating layer of the basic zinc carbonate , Zn 5 (OH) 6 (CO 3 ) 2 , by reaction with atmospheric carbon dioxide . Zinc burns in air with a bright bluish-green flame, giving off fumes of zinc oxide . Zinc reacts readily with acids , alkalis and other non-metals. Extremely pure zinc reacts only slowly at room temperature with acids. Strong acids, such as hydrochloric or sulfuric acid , can remove

3100-812: Is an ongoing area of scientific study. The lightest elements are hydrogen and helium , both created by Big Bang nucleosynthesis in the first 20 minutes of the universe in a ratio of around 3:1 by mass (or 12:1 by number of atoms), along with tiny traces of the next two elements, lithium and beryllium . Almost all other elements found in nature were made by various natural methods of nucleosynthesis . On Earth, small amounts of new atoms are naturally produced in nucleogenic reactions, or in cosmogenic processes, such as cosmic ray spallation . New atoms are also naturally produced on Earth as radiogenic daughter isotopes of ongoing radioactive decay processes such as alpha decay , beta decay , spontaneous fission , cluster decay , and other rarer modes of decay. Of

3224-460: Is based on a Latin or other traditional word, for example adopting "gold" rather than "aurum" as the name for the 79th element (Au). IUPAC prefers the British spellings " aluminium " and "caesium" over the U.S. spellings "aluminum" and "cesium", and the U.S. "sulfur" over British "sulphur". However, elements that are practical to sell in bulk in many countries often still have locally used national names, and countries whose national language does not use

3348-542: Is being smelted. In Britain, John Lane is said to have carried out experiments to smelt zinc, probably at Landore , prior to his bankruptcy in 1726. In 1738 in Great Britain, William Champion patented a process to extract zinc from calamine in a vertical retort -style smelter. His technique resembled that used at Zawar zinc mines in Rajasthan , but no evidence suggests he visited the Orient. Champion's process

3472-522: 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. Zinc is a fair conductor of electricity . For a metal, zinc has relatively low melting (419.5 °C) and boiling point (907 °C). The melting point is the lowest of all the d-block metals aside from mercury and cadmium ; for this reason among others, zinc, cadmium, and mercury are often not considered to be transition metals like

3596-460: Is implicated by the formation of a yellow diamagnetic glass by dissolving metallic zinc in molten ZnCl 2 . The [Zn 2 ] core would be analogous to the [Hg 2 ] cation present in mercury (I) compounds. The diamagnetic nature of the ion confirms its dimeric structure. The first zinc(I) compound containing the Zn–Zn bond, (η-C 5 Me 5 ) 2 Zn 2 . Binary compounds of zinc are known for most of

3720-406: Is known as Special High Grade, often abbreviated SHG , and is 99.995% pure. Worldwide, 95% of new zinc is mined from sulfidic ore deposits, in which sphalerite (ZnS) is nearly always mixed with the sulfides of copper, lead and iron. Zinc mines are scattered throughout the world, with the main areas being China, Australia, and Peru. China produced 38% of the global zinc output in 2014. Zinc metal

3844-539: Is necessary for prenatal and postnatal development. It is the second most abundant trace metal in humans after iron and it is the only metal which appears in all enzyme classes . Zinc is also an essential nutrient element for coral growth as it is an important cofactor for many enzymes. Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, and diarrhea . Enzymes with

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3968-523: Is necessary for the leaching process. If deposits of zinc carbonate , zinc silicate , or zinc-spinel (like the Skorpion Deposit in Namibia ) are used for zinc production, the roasting can be omitted. For further processing two basic methods are used: pyrometallurgy or electrowinning . Pyrometallurgy reduces zinc oxide with carbon or carbon monoxide at 950 °C (1,740 °F) into

4092-420: Is not being used, because the ammonium chloride inside the battery reacts with the zinc. An "inside-out" form with a carbon cup and zinc vanes on the interior, while more leak-resistant, has not been manufactured since the 1960s. This picture shows the zinc container of fresh batteries at (a), and discharged batteries at (b) and (c). The battery shown at (c) had a polyethylene protection film (mostly removed in

4216-436: Is often used in characterizing the elements. Density is often expressed in grams per cubic centimetre (g/cm ). Since several elements are gases at commonly encountered temperatures, their densities are usually stated for their gaseous forms; when liquefied or solidified, the gaseous elements have densities similar to those of the other elements. When an element has allotropes with different densities, one representative allotrope

4340-473: Is probably calamine brass. The oldest known pills were made of the zinc carbonates hydrozincite and smithsonite. The pills were used for sore eyes and were found aboard the Roman ship Relitto del Pozzino , wrecked in 140 BC. The Berne zinc tablet is a votive plaque dating to Roman Gaul made of an alloy that is mostly zinc. The Charaka Samhita , thought to have been written between 300 and 500 AD, mentions

4464-430: Is produced using extractive metallurgy . The ore is finely ground, then put through froth flotation to separate minerals from gangue (on the property of hydrophobicity ), to get a zinc sulfide ore concentrate consisting of about 50% zinc, 32% sulfur, 13% iron, and 5% SiO 2 . Roasting converts the zinc sulfide concentrate to zinc oxide: The sulfur dioxide is used for the production of sulfuric acid, which

4588-636: Is the 24th most abundant element in Earth's crust and has five stable isotopes . The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting , and final extraction using electricity ( electrowinning ). Zinc is an essential trace element for humans, animals, plants and for microorganisms and

4712-426: Is the mass number) is an atom with 24 nucleons (12 protons and 12 neutrons). Whereas the mass number simply counts the total number of neutrons and protons and is thus an integer, the atomic mass of a particular isotope (or "nuclide") of the element is the mass of a single atom of that isotope, and is typically expressed in daltons (symbol: Da), or universal atomic mass units (symbol: u). Its relative atomic mass

4836-527: Is the most heavily mined zinc-containing ore because its concentrate contains 60–62% zinc. Other source minerals for zinc 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 by weathering of the primordial zinc sulfides. Identified world zinc resources total about 1.9–2.8 billion tonnes . Large deposits are in Australia, Canada and

4960-410: Is the negatively charged terminal. The zinc is oxidised by the charge carrier , chloride anion (Cl ) into ZnCl 2 , via the following half-reactions : Anode (oxidation reaction, marked −) Cathode (reduction reaction, marked +) Other side reactions are possible, but the overall reaction in a zinc–carbon cell can be represented as If zinc chloride is substituted for ammonium chloride as

5084-532: Is typically selected in summary presentations, while densities for each allotrope can be stated where more detail is provided. For example, the three familiar allotropes of carbon ( amorphous carbon , graphite , and diamond ) have densities of 1.8–2.1, 2.267, and 3.515 g/cm , respectively. The elements studied to date as solid samples have eight kinds of crystal structures : cubic , body-centered cubic , face-centered cubic, hexagonal , monoclinic , orthorhombic , rhombohedral , and tetragonal . For some of

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5208-492: Is used and offering about twice the service life of general-purpose zinc–carbon cells, or up to four times in continuous-use or high-drain applications. This is still a fraction of the output of an alkaline cell, however. Alkaline batteries offer up to eight times the battery life of zinc–carbon batteries, especially in continuous-use or high-drain applications. Manufacturers recommend storage of zinc–carbon batteries at room temperature; storage at higher temperatures reduces

5332-540: Is used in modern cells, which is thinner and allows more manganese dioxide to be used. Originally cells were sealed with a layer of asphalt to prevent drying out of the electrolyte; more recently, a thermoplastic washer seal is used to help prevent leakage as well as to contain any internal pressure which may form as a result of hydrogen gas buildup during discharge. The carbon rod is slightly porous, which allows more charged hydrogen atoms to combine forming hydrogen gas. The ratio of manganese dioxide and carbon powder in

5456-417: Is used in two different but closely related meanings: it can mean a chemical substance consisting of a single kind of atoms, or it can mean that kind of atoms as a component of various chemical substances. For example, molecules of water (H 2 O) contain atoms of hydrogen (H) and oxygen (O), so water can be said as a compound consisting of the elements hydrogen (H) and oxygen (O) even though it does not contain

5580-429: Is very strong; fullerenes , which have nearly spherical shapes; and carbon nanotubes , which are tubes with a hexagonal structure (even these may differ from each other in electrical properties). The ability of an element to exist in one of many structural forms is known as 'allotropy'. The reference state of an element is defined by convention, usually as the thermodynamically most stable allotrope and physical state at

5704-590: Is widely used. For example, the French chemical terminology distinguishes élément chimique (kind of atoms) and corps simple (chemical substance consisting of a single kind of atoms); the Russian chemical terminology distinguishes химический элемент and простое вещество . Almost all baryonic matter in the universe is composed of elements (among rare exceptions are neutron stars ). When different elements undergo chemical reactions, atoms are rearranged into new compounds held together by chemical bonds . Only

5828-489: The International Union of Pure and Applied Chemistry (IUPAC) had recognized a total of 118 elements. The first 94 occur naturally on Earth , and the remaining 24 are synthetic elements produced in nuclear reactions. Save for unstable radioactive elements (radioelements) which decay quickly, nearly all elements are available industrially in varying amounts. The discovery and synthesis of further new elements

5952-638: The Latin alphabet are likely to use the IUPAC element names. According to IUPAC, element names are not proper nouns; therefore, the full name of an element is not capitalized in English, even if derived from a proper noun , as in californium and einsteinium . Isotope names are also uncapitalized if written out, e.g., carbon-12 or uranium-235 . Chemical element symbols (such as Cf for californium and Es for einsteinium), are always capitalized (see below). In

6076-746: The New World . It was used extensively as such by American publications before the international standardization (in 1950). Before chemistry became a science , alchemists designed arcane symbols for both metals and common compounds. These were however used as abbreviations in diagrams or procedures; there was no concept of atoms combining to form molecules . With his advances in the atomic theory of matter, John Dalton devised his own simpler symbols, based on circles, to depict molecules. Zinc%E2%80%93carbon battery General-purpose batteries may use an acidic aqueous paste of ammonium chloride (NH 4 Cl) as electrolyte, with some zinc chloride solution on

6200-423: The kinetic isotope effect is significant). Thus, all carbon isotopes have nearly identical chemical properties because they all have six electrons, even though they may have 6 to 8 neutrons. That is why atomic number, rather than mass number or atomic weight , is considered the identifying characteristic of an element. The symbol for atomic number is Z . Isotopes are atoms of the same element (that is, with

6324-467: The metalloids and all the nonmetals except the noble gases . The oxide ZnO is a white powder that is nearly insoluble in neutral aqueous solutions, but is amphoteric , dissolving in both strong basic and acidic solutions. The other chalcogenides ( ZnS , ZnSe , and ZnTe ) have varied applications in electronics and optics. Pnictogenides ( Zn 3 N 2 , Zn 3 P 2 , Zn 3 As 2 and Zn 3 Sb 2 ),

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6448-405: The nuclear binding energy and electron binding energy. For example, the atomic mass of chlorine-35 to five significant digits is 34.969 Da and that of chlorine-37 is 36.966 Da. However, the relative atomic mass of each isotope is quite close to its mass number (always within 1%). The only isotope whose atomic mass is exactly a natural number is C, which has a mass of 12 Da; because

6572-515: The spinal cord of a freshly dissected frog to an iron rail attached by a brass hook caused the frog's leg to twitch. He incorrectly thought he had discovered an ability of nerves and muscles to create electricity and called the effect " animal electricity ". The galvanic cell and the process of galvanization were both named for Luigi Galvani, and his discoveries paved the way for electrical batteries , galvanization, and cathodic protection . Galvani's friend, Alessandro Volta , continued researching

6696-400: The 12th to 16th centuries. Another estimate gives a total production of 60,000 tonnes of metallic zinc over this period. The Rasaratna Samuccaya , written in approximately the 13th century AD, mentions two types of zinc-containing ores: one used for metal extraction and another used for medicinal purposes. Zinc was distinctly recognized as a metal under the designation of Yasada or Jasada in

6820-613: 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

6944-417: The 24th most abundant element. It also makes up 312 ppm of the solar system, where it is the 22nd most abundant element. Typical background concentrations of zinc do not exceed 1 μg/m in the atmosphere; 300 mg/kg in soil; 100 mg/kg in vegetation; 20 μg/L in freshwater and 5 μg/L in seawater. The element is normally found in association with other base metals such as copper and lead in ores . Zinc

7068-638: The 94 naturally occurring elements, those with atomic numbers 1 through 82 each have at least one stable isotope (except for technetium , element 43 and promethium , element 61, which have no stable isotopes). Isotopes considered stable are those for which no radioactive decay has yet been observed. Elements with atomic numbers 83 through 94 are unstable to the point that radioactive decay of all isotopes can be detected. Some of these elements, notably bismuth (atomic number 83), thorium (atomic number 90), and uranium (atomic number 92), have one or more isotopes with half-lives long enough to survive as remnants of

7192-487: The French, Italians, Greeks, Portuguese and Poles prefer "azote/azot/azoto" (from roots meaning "no life") for "nitrogen". For purposes of international communication and trade, the official names of the chemical elements both ancient and more recently recognized are decided by the International Union of Pure and Applied Chemistry (IUPAC), which has decided on a sort of international English language, drawing on traditional English names even when an element's chemical symbol

7316-476: The United Kingdom and 18% in the E.U. The container of the zinc–carbon dry cell is a zinc can (anode). The bottom and sides of the can contains a paper separator layer which is impregnated with ammonium chloride ( NH 4 Cl ) along with a thickening agent to form an aqueous electrolyte paste. The paper separator prevents a short circuit from forming by protecting the zinc can from making contact with

7440-474: The United States, with the largest reserves in Iran . The most recent estimate of reserve base for zinc (meets specified minimum physical criteria related to current mining and production practices) was made in 2009 and calculated to be roughly 480 Mt. Zinc reserves, on the other hand, are geologically identified ore bodies whose suitability for recovery is economically based (location, grade, quality, and quantity) at

7564-412: The active chemicals increases the internal resistance of the battery, which causes the terminal voltage to drop under load. The zinc-chloride cell, frequently referred to as a heavy-duty , extra-heavy-duty , super-heavy-duty , or super-extra-heavy-duty battery, is an improvement on the original zinc–carbon cell, using purer chemicals and giving a longer service life and steadier voltage output as it

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7688-487: The atomic masses of the elements (their atomic weights or atomic masses) do not always increase monotonically with their atomic numbers. The naming of various substances now known as elements precedes the atomic theory of matter, as names were given locally by various cultures to various minerals, metals, compounds, alloys, mixtures, and other materials, though at the time it was not known which chemicals were elements and which compounds. As they were identified as elements,

7812-411: The cathode paste affects the characteristics of the cell: more carbon powder lowers internal resistance , while more manganese dioxide improves storage capacity. Flat cells are made for assembly into batteries with higher voltages, up to about 450 volts. Flat cells are stacked and the whole assembly is coated in wax to prevent electrolyte evaporation . Electrons flow from the anode to cathode through

7936-455: The cathode, which is a mixture of powdered carbon (usually graphite powder) and manganese (IV) oxide ( MnO 2 ), which is packed around a carbon rod. Carbon is the only practical conductor material because every common metal quickly corrodes in the positive electrode when in the presence of a salt-based electrolyte. Early types, and low-cost cells, use a separator consisting of a layer of starch or flour . A layer of starch-coated paper

8060-413: The chemical substances (di)hydrogen (H 2 ) and (di)oxygen (O 2 ), as H 2 O molecules are different from H 2 and O 2 molecules. For the meaning "chemical substance consisting of a single kind of atoms", the terms "elementary substance" and "simple substance" have been suggested, but they have not gained much acceptance in English chemical literature, whereas in some other languages their equivalent

8184-418: The chromate ZnCrO 4 (one of the few colored zinc compounds) are a few examples of other common inorganic compounds of zinc. Organozinc compounds are those that contain zinc– carbon covalent bonds. Diethylzinc ( (C 2 H 5 ) 2 Zn ) is a reagent in synthetic chemistry. It was first reported in 1848 from the reaction of zinc and ethyl iodide , and was the first compound known to contain

8308-408: The dalton is defined as 1/12 of the mass of a free neutral carbon-12 atom in the ground state. The standard atomic weight (commonly called "atomic weight") of an element is the average of the atomic masses of all the chemical element's isotopes as found in a particular environment, weighted by isotopic abundance, relative to the atomic mass unit. This number may be a fraction that is not close to

8432-416: The discovery and use of elements began with early human societies that discovered native minerals like carbon , sulfur , copper and gold (though the modern concept of an element was not yet understood). Attempts to classify materials such as these resulted in the concepts of classical elements , alchemy , and similar theories throughout history. Much of the modern understanding of elements developed from

8556-568: The effect and invented the Voltaic pile in 1800. Volta's pile consisted of a stack of simplified galvanic cells , each being one plate of copper and one of zinc connected by an electrolyte . By stacking these units in series, the Voltaic pile (or "battery") as a whole had a higher voltage, which could be used more easily than single cells. Electricity is produced because the Volta potential between

8680-429: The electrolyte, the anode reaction remains the same: and the cathode reaction produces zinc hydroxide and manganese(III) oxide . giving the overall reaction The battery has an electromotive force (e.m.f.) of about 1.5 V . The approximate nature of the e.m.f is related to the complexity of the cathode reaction. The anode (zinc) reaction is comparatively simple with a known potential. Side reactions and depletion of

8804-406: The elements are available by name, atomic number, density, melting point, boiling point and chemical symbol , as well as ionization energy . The nuclides of stable and radioactive elements are also available as a list of nuclides , sorted by length of half-life for those that are unstable. One of the most convenient, and certainly the most traditional presentation of the elements, is in the form of

8928-470: The elements are often summarized using the periodic table, which powerfully and elegantly organizes the elements by increasing atomic number into rows ( "periods" ) in which the columns ( "groups" ) share recurring ("periodic") physical and chemical properties. The table contains 118 confirmed elements as of 2021. Although earlier precursors to this presentation exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869, who intended

9052-480: The elements can be uniquely sequenced by atomic number, conventionally from lowest to highest (as in a periodic table), sets of elements are sometimes specified by such notation as "through", "beyond", or "from ... through", as in "through iron", "beyond uranium", or "from lanthanum through lutetium". The terms "light" and "heavy" are sometimes also used informally to indicate relative atomic numbers (not densities), as in "lighter than carbon" or "heavier than lead", though

9176-413: The elements without any stable isotopes are technetium (atomic number 43), promethium (atomic number 61), and all observed elements with atomic number greater than 82. Of the 80 elements with at least one stable isotope, 26 have only one stable isotope. The mean number of stable isotopes for the 80 stable elements is 3.1 stable isotopes per element. The largest number of stable isotopes for a single element

9300-474: The elements, including consideration of their general physical and chemical properties, their states of matter under familiar conditions, their melting and boiling points, their densities, their crystal structures as solids, and their origins. Several terms are commonly used to characterize the general physical and chemical properties of the chemical elements. A first distinction is between metals , which readily conduct electricity , nonmetals , which do not, and

9424-492: The existing names for anciently known elements (e.g., gold, mercury, iron) were kept in most countries. National differences emerged over the element names either for convenience, linguistic niceties, or nationalism. For example, German speakers use "Wasserstoff" (water substance) for "hydrogen", "Sauerstoff" (acid substance) for "oxygen" and "Stickstoff" (smothering substance) for "nitrogen"; English and some other languages use "sodium" for "natrium", and "potassium" for "kalium"; and

9548-400: The expected service life . Zinc–carbon batteries may be frozen without damage; manufacturers recommend that they be returned to normal room temperature before use, and that condensation on the battery jacket must be avoided. By the end of the 20th century, the storage life of zinc–carbon cells had improved fourfold over expected life in 1910. Zinc–carbon cells have a short shelf life , as

9672-630: The explosive stellar nucleosynthesis that produced the heavy metals before the formation of our Solar System . At over 1.9 × 10 years, over a billion times longer than the estimated age of the universe, bismuth-209 has the longest known alpha decay half-life of any isotope, and is almost always considered on par with the 80 stable elements. The heaviest elements (those beyond plutonium, element 94) undergo radioactive decay with half-lives so short that they are not found in nature and must be synthesized . There are now 118 known elements. In this context, "known" means observed well enough, even from just

9796-434: The formation of Zn 2 Cl 2 , a zinc compound with a +1 oxidation state. No compounds of zinc in positive oxidation states other than +1 or +2 are known. Calculations indicate that a zinc compound with the oxidation state of +4 is unlikely to exist. Zn(III) is predicted to exist in the presence of strongly electronegative trianions; however, there exists some doubt around this possibility. But in 2021 another compound

9920-529: The formation of Earth, they are certain to have completely decayed, and if present in novae, are in quantities too small to have been noted. Technetium was the first purportedly non-naturally occurring element synthesized, in 1937, though trace amounts of technetium have since been found in nature (and also the element may have been discovered naturally in 1925). This pattern of artificial production and later natural discovery has been repeated with several other radioactive naturally occurring rare elements. List of

10044-431: The half-lives predicted for the observationally stable lead isotopes range from 10 to 10 years. Elements with atomic numbers 43, 61, and 83 through 94 are unstable enough that their radioactive decay can be detected. Three of these elements, bismuth (element 83), thorium (90), and uranium (92) have one or more isotopes with half-lives long enough to survive as remnants of the explosive stellar nucleosynthesis that produced

10168-399: The heaviest elements also undergo spontaneous fission . Isotopes that are not radioactive, are termed "stable" isotopes. All known stable isotopes occur naturally (see primordial nuclide ). The many radioisotopes that are not found in nature have been characterized after being artificially produced. Certain elements have no stable isotopes and are composed only of radioisotopes: specifically

10292-549: The heavy elements before the formation of the Solar System. For example, at over 1.9 × 10 years, over a billion times longer than the estimated age of the universe, bismuth-209 has the longest known alpha decay half-life of any isotope. The last 24 elements (those beyond plutonium, element 94) undergo radioactive decay with short half-lives and cannot be produced as daughters of longer-lived elements, and thus are not known to occur in nature at all. 1 The properties of

10416-460: The hydroxide Zn(OH) 2 forms as a white precipitate . In stronger alkaline solutions, this hydroxide is dissolved to form zincates ( [Zn(OH) 4 ] ). The nitrate Zn(NO 3 ) 2 , chlorate Zn(ClO 3 ) 2 , sulfate ZnSO 4 , phosphate Zn 3 (PO 4 ) 2 , molybdate ZnMoO 4 , cyanide Zn(CN) 2 , arsenite Zn(AsO 2 ) 2 , arsenate Zn(AsO 4 ) 2 ·8H 2 O and

10540-401: The longer-lasting alkaline batteries . By 1876, the wet Leclanché cell was made with a compressed block of manganese dioxide. In 1886, Carl Gassner patented a "dry" version by using a casing made of zinc sheet metal as the anode and a paste of plaster of Paris (and later, graphite powder). In 1898, Conrad Hubert used consumer batteries manufactured by W. H. Lawrence to power what

10664-455: The medical Lexicon ascribed to the Hindu king Madanapala (of Taka dynasty) 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

10788-425: The metal, which is distilled as zinc vapor to separate it from other metals, which are not volatile at those temperatures. The zinc vapor is collected in a condenser. The equations below describe this process: In electrowinning , zinc is leached from the ore concentrate by sulfuric acid and impurities are precipitated: Chemical element A chemical element is a chemical substance whose atoms all have

10912-417: The organic laboratory. Zinc 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 , with a distorted form of hexagonal close packing , in which each atom has six nearest neighbors (at 265.9 pm) in its own plane and six others at a greater distance of 290.6 pm. The metal

11036-521: The passivating layer and the subsequent reaction with the acid releases hydrogen gas. The chemistry of zinc is dominated by the +2 oxidation state. When compounds in this oxidation state are formed, the outer shell s electrons are lost, yielding a bare zinc ion with the electronic configuration [Ar]3d. In aqueous solution an octahedral complex, [Zn(H 2 O) 6 ] is the predominant species. The volatilization of zinc in combination with zinc chloride at temperatures above 285 °C indicates

11160-418: The periodic table, which groups together elements with similar chemical properties (and usually also similar electronic structures). The atomic number of an element is equal to the number of protons in each atom, and defines the element. For example, all carbon atoms contain 6 protons in their atomic nucleus ; so the atomic number of carbon is 6. Carbon atoms may have different numbers of neutrons; atoms of

11284-426: The periodic tables presented here includes: actinides , alkali metals , alkaline earth metals , halogens , lanthanides , transition metals , post-transition metals , metalloids , reactive nonmetals , and noble gases . In this system, the alkali metals, alkaline earth metals, and transition metals, as well as the lanthanides and the actinides, are special groups of the metals viewed in a broader sense. Similarly,

11408-404: The peroxide ( ZnO 2 ), the hydride ( ZnH 2 ), and the carbide ( ZnC 2 ) are also known. Of the four halides , ZnF 2 has the most ionic character, while the others ( ZnCl 2 , ZnBr 2 , and ZnI 2 ) have relatively low melting points and are considered to have more covalent character. In weak basic solutions containing Zn ions,

11532-518: The photo) to keep the zinc oxide inside the casing. Disposal varies by jurisdiction. For example, in the U.S., the state of California considers all batteries as hazardous waste when discarded, and has banned the disposal of batteries with other domestic waste . In Europe, battery disposal is controlled by the WEEE Directive and Battery Directive regulations, and as such zinc–carbon batteries must not be thrown out with domestic waste. In

11656-412: The pure element to exist in multiple chemical structures ( spatial arrangements of atoms ), known as allotropes , which differ in their properties. For example, carbon can be found as diamond , which has a tetrahedral structure around each carbon atom; graphite , which has layers of carbon atoms with a hexagonal structure stacked on top of each other; graphene , which is a single layer of graphite that

11780-772: The reactive nonmetals and the noble gases are nonmetals viewed in the broader sense. In some presentations, the halogens are not distinguished, with astatine identified as a metalloid and the others identified as nonmetals. Another commonly used basic distinction among the elements is their state of matter (phase), whether solid , liquid , or gas , at standard temperature and pressure (STP). Most elements are solids at STP, while several are gases. Only bromine and mercury are liquid at 0 degrees Celsius (32 degrees Fahrenheit) and 1 atmosphere pressure; caesium and gallium are solid at that temperature, but melt at 28.4°C (83.2°F) and 29.8°C (85.6°F), respectively. Melting and boiling points , typically expressed in degrees Celsius at

11904-478: The remainder, have been found that are 2,500 years old. A possibly prehistoric statuette containing 87.5% zinc was found in a Dacian archaeological site. Strabo writing in the 1st century BC (but quoting a now lost work of the 4th century BC historian Theopompus ) mentions "drops of false silver" which when mixed with copper make brass. This may refer to small quantities of zinc that is a by-product of smelting sulfide ores. Zinc in such remnants in smelting ovens

12028-919: The remaining 11 elements have half lives too short for them to have been present at the beginning of the Solar System, and are therefore considered transient elements. Of these 11 transient elements, five ( polonium , radon , radium , actinium , and protactinium ) are relatively common decay products of thorium and uranium . The remaining six transient elements (technetium, promethium, astatine, francium , neptunium , and plutonium ) occur only rarely, as products of rare decay modes or nuclear reaction processes involving uranium or other heavy elements. Elements with atomic numbers 1 through 82, except 43 (technetium) and 61 (promethium), each have at least one isotope for which no radioactive decay has been observed. Observationally stable isotopes of some elements (such as tungsten and lead ), however, are predicted to be slightly radioactive with very long half-lives: for example,

12152-534: The reserve lifetime for zinc has remained unchanged. About 346 million tonnes have been extracted throughout history to 2002, and scholars have estimated that about 109–305 million tonnes are in use. Five stable isotopes of zinc occur in nature, with Zn being the most abundant isotope (49.17% natural abundance ). The other isotopes found in nature are Zn (27.73%), Zn (4.04%), Zn (18.45%), and Zn (0.61%). Several dozen radioisotopes have been characterized. Zn , which has

12276-494: The rest of the d-block metals. Many alloys contain zinc, 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 . Although neither zinc nor zirconium is ferromagnetic , their alloy, ZrZn 2 , exhibits ferromagnetism below 35  K . Zinc makes up about 75  ppm  (0.0075%) of Earth's crust , making it

12400-524: The same crystal structure , and in other circumstances where ionic radius is a determining factor, the chemistry of zinc has much in common with that of magnesium. In other respects, there is little similarity with the late first-row transition metals. Zinc tends to form bonds with a greater degree of covalency and much more stable complexes with N - and S - donors. Complexes of zinc are mostly 4- or 6- coordinate , although 5-coordinate complexes are known. Zinc(I) compounds are very rare. The [Zn 2 ] ion

12524-495: The same element having different numbers of neutrons are known as isotopes of the element. The number of protons in the nucleus also determines its electric charge , which in turn determines the number of electrons of the atom in its non-ionized state. The electrons are placed into atomic orbitals that determine the atom's chemical properties . The number of neutrons in a nucleus usually has very little effect on an element's chemical properties; except for hydrogen (for which

12648-404: The same number of protons in their nucleus), but having different numbers of neutrons . Thus, for example, there are three main isotopes of carbon. All carbon atoms have 6 protons, but they can have either 6, 7, or 8 neutrons. Since the mass numbers of these are 12, 13 and 14 respectively, said three isotopes are known as carbon-12 , carbon-13 , and carbon-14 ( C, C, and C). Natural carbon

12772-834: The same number of protons . The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8, meaning each oxygen atom has 8 protons in its nucleus. Atoms of the same element can have different numbers of neutrons in their nuclei, known as isotopes of the element. Two or more atoms can combine to form molecules . Some elements are formed from molecules of identical atoms , e. g. atoms of hydrogen (H) form diatomic molecules (H 2 ). Chemical compounds are substances made of atoms of different elements; they can have molecular or non-molecular structure. Mixtures are materials containing different chemical substances; that means (in case of molecular substances) that they contain different types of molecules. Atoms of one element can be transformed into atoms of

12896-457: The second half of the 20th century, physics laboratories became able to produce elements with half-lives too short for an appreciable amount of them to exist at any time. These are also named by IUPAC, which generally adopts the name chosen by the discoverer. This practice can lead to the controversial question of which research group actually discovered an element, a question that delayed the naming of elements with atomic number of 104 and higher for

13020-594: The second known zinc-containing enzyme in 1955. Zinc is the fourth most common metal in use, trailing only iron , aluminium , and copper with an annual production of about 13 million tonnes. The world's largest zinc producer is Nyrstar , a merger of the Australian OZ Minerals and the Belgian Umicore . About 70% of the world's zinc originates from mining, while the remaining 30% comes from recycling secondary zinc. Commercially pure zinc

13144-496: The synthetically produced transuranic elements, available samples have been too small to determine crystal structures. Chemical elements may also be categorized by their origin on Earth, with the first 94 considered naturally occurring, while those with atomic numbers beyond 94 have only been produced artificially via human-made nuclear reactions. Of the 94 naturally occurring elements, 83 are considered primordial and either stable or weakly radioactive. The longest-lived isotopes of

13268-955: The table to illustrate recurring trends in the properties of the elements. The layout of the table has been refined and extended over time as new elements have been discovered and new theoretical models have been developed to explain chemical behavior. Use of the periodic table is now ubiquitous in chemistry, providing an extremely useful framework to classify, systematize and compare all the many different forms of chemical behavior. The table has also found wide application in physics , geology , biology , materials science , engineering , agriculture , medicine , nutrition , environmental health , and astronomy . Its principles are especially important in chemical engineering . The various chemical elements are formally identified by their unique atomic numbers, their accepted names, and their chemical symbols . The known elements have atomic numbers from 1 to 118, conventionally presented as Arabic numerals . Since

13392-533: The time of determination. Since exploration and mine development is an ongoing process, the amount of zinc reserves is not a fixed number and sustainability of zinc ore supplies cannot be judged by simply extrapolating the combined mine life of today's zinc mines. This concept is well supported by data from the United States Geological Survey (USGS), which illustrates that although refined zinc production increased 80% between 1990 and 2010,

13516-420: The two metal plates makes electrons flow from the zinc to the copper and corrode the zinc. The non-magnetic character of zinc and its lack of color in solution delayed discovery of its importance to biochemistry and nutrition. This changed in 1940 when carbonic anhydrase , an enzyme that scrubs carbon dioxide from blood, was shown to have zinc in its active site . The digestive enzyme carboxypeptidase became

13640-621: The universe at large, in the spectra of stars and also supernovae, where short-lived radioactive elements are newly being made. The first 94 elements have been detected directly on Earth as primordial nuclides present from the formation of the Solar System , or as naturally occurring fission or transmutation products of uranium and thorium. The remaining 24 heavier elements, not found today either on Earth or in astronomical spectra, have been produced artificially: all are radioactive, with short half-lives; if any of these elements were present at

13764-496: The use of impure zinc in ancient times have been discovered. Zinc ores were used to make the zinc–copper alloy brass thousands of years prior to the discovery of zinc as a separate element. Judean brass from the 14th to 10th centuries BC contains 23% zinc. Knowledge of how to produce brass spread to Ancient Greece by the 7th century BC, but few varieties were made. Ornaments made of alloys containing 80–90% zinc, with lead, iron, antimony , and other metals making up

13888-485: The use of purer grades of manganese dioxide, the addition of graphite powder to the manganese dioxide to lower internal resistance , better sealing, and purer zinc for the negative electrode. Zinc-chloride cells (usually marketed as "heavy duty" batteries) use a higher concentration of anolyte (or anode electrolyte) which is primarily composed of zinc chloride, which can produce a more consistent voltage output in high drain applications. Side reactions between impurities in

14012-403: The wire of the attached device. Zinc–carbon batteries have a lower per unit cost and are often used as power for appliances that consume little energy, like remote controls for television, clocks, and smoke detectors . Zinc-carbon batteries were in common use with hand-cranked telephone magneto phones, powering the microphone and speaker. In a zinc–carbon dry cell, the outer zinc container

14136-528: The work of Dmitri Mendeleev , a Russian chemist who published the first recognizable periodic table in 1869. This table organizes the elements by increasing atomic number into rows (" periods ") in which the columns (" groups ") share recurring ("periodic") physical and chemical properties . The periodic table summarizes various properties of the elements, allowing chemists to derive relationships between them and to make predictions about elements not yet discovered, and potential new compounds. By November 2016,

14260-403: The zinc is attacked by ammonium chloride. The zinc container becomes thinner as the cell is used, because zinc metal is oxidized to zinc ions. When the zinc case thins enough, zinc chloride begins to leak out of the battery. The old dry cell is not leak-proof and becomes very sticky as the paste leaks through the holes in the zinc case. The zinc casing in the dry cell gets thinner even when the cell

14384-511: The zinc metal/zinc chloride anode, and the ammonium chloride electrolyte can increase the self-discharge rate and promote corrosion of the cell. Formerly, the zinc was coated with mercury (Hg) to form an amalgam , protecting it. Given that this is an environmental hazard, current production batteries no longer use mercury. Manufacturers must now use more highly purified zinc to prevent local action and self-discharge. As of 2011, zinc–carbon batteries accounted for 20% of all portable batteries in

14508-589: Was isolated in Europe, it was imported from India in about 1600 CE. Postlewayt 's Universal Dictionary , a contemporary source giving technological information in Europe, did not mention zinc before 1751 but the element was studied before then. Flemish metallurgist and alchemist P. M. de Respour reported that he had extracted metallic zinc from zinc oxide in 1668. By the start of the 18th century, Étienne François Geoffroy described how zinc oxide condenses as yellow crystals on bars of iron placed above zinc ore that

14632-474: Was known to the ancient Romans and Greeks. The mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. The oldest evidence of pure zinc comes from Zawar, in Rajasthan, as early as the 9th century AD when a distillation process was employed to make pure zinc. Alchemists burned zinc in air to form what they called " philosopher's wool " or "white snow". The element

14756-786: 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 zinc 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 zinc. 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 zinc gluconate (as dietary supplements), zinc chloride (in deodorants), zinc pyrithione (anti- dandruff shampoos), zinc sulfide (in luminescent paints), and dimethylzinc or diethylzinc in

14880-419: Was reported with more evidence that had the oxidation state of +3 with the formula ZnBeB 11 (CN) 12 . Zinc chemistry is similar to the chemistry of the late first-row transition metals, nickel and copper, though it has a filled d-shell and compounds are diamagnetic and mostly colorless. The ionic radii of zinc and magnesium happen to be nearly identical. Because of this some of the equivalent salts have

15004-589: Was the first flashlight , and subsequently the two formed the Eveready Battery Company . In 1900, Gassner demonstrated dry cells for portable lighting at the World's Fair in Paris . Continual improvements were made to the stability and capacity of zinc–carbon cells throughout the 20th century; by the end of the century the capacities had increased fourfold over the 1910 equivalent. Improvements include

15128-536: Was used as early as the third millennium BC in the Aegean area and the region which currently includes Iraq , the United Arab Emirates , Kalmykia , Turkmenistan and Georgia . In the second millennium BC it was used in the regions currently including West India , Uzbekistan , Iran , Syria , Iraq, and Israel . Zinc metal was not produced on a large scale until the 12th century in India, though it

15252-502: Was used through 1851. German chemist Andreas Marggraf normally gets credit for isolating pure metallic zinc in the West, even though Swedish chemist Anton von Swab had distilled zinc from calamine four years previously. In his 1746 experiment, Marggraf heated a mixture of calamine and charcoal in a closed vessel without copper to obtain a metal. This procedure became commercially practical by 1752. William Champion's brother, John, patented

15376-524: Was usually discarded as it was thought to be worthless. The manufacture of brass was known to the Romans by about 30 BC. They made brass by heating powdered calamine (zinc silicate or carbonate), charcoal and copper together in a crucible. The resulting calamine brass was then either cast or hammered into shape for use in weaponry. Some coins struck by Romans in the Christian era are made of what

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