131-509: Cobalt is a chemical element ; it has symbol Co and atomic number 27. As with nickel , cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron . The free element , produced by reductive smelting , is a hard, lustrous, somewhat brittle, gray metal . Cobalt-based blue pigments ( cobalt blue ) have been used since antiquity for jewelry and paints, and to impart
262-410: A gnome (mine spirit) by others. Cobalt is a ferromagnetic metal with a specific gravity of 8.9. The Curie temperature is 1,115 °C (2,039 °F) and the magnetic moment is 1.6–1.7 Bohr magnetons per atom . Cobalt has a relative permeability two-thirds that of iron . Metallic cobalt occurs as two crystallographic structures : hcp and fcc . The ideal transition temperature between
393-426: A hydride ion . Reductants in chemistry are very diverse. Electropositive elemental metals , such as lithium , sodium , magnesium , iron , zinc , and aluminium , are good reducing agents. These metals donate electrons relatively readily. Hydride transfer reagents , such as NaBH 4 and LiAlH 4 , reduce by atom transfer: they transfer the equivalent of hydride or H . These reagents are widely used in
524-738: 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
655-581: A bucket used in mining, frequently mentioned by Agricola, namely the kobel/köbel (Latinized as modulus ). Another theory given by the Etymologisches Wörterbuch derives the term from kōbathium or rather cobathia ( κωβάθια , "arsenic sulfide") which occurs as noxious fumes. An etymology from Slavonic kowalti was suggested by Emanuel Merck (1902). W. W. Skeat and J. Berendes construed κόβαλος as "parasite", i.e. as an ore parasitic to nickel , but this explanation
786-549: 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
917-477: 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"
1048-451: A distinctive blue tint to glass. The color was long thought to be due to the metal bismuth . Miners had long used the name kobold ore ( German for goblin ore ) for some of the blue pigment-producing minerals . They were so named because they were poor in known metals and gave off poisonous arsenic -containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), which
1179-652: 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
1310-529: 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
1441-411: A gas. Later, scientists realized that the metal atom gains electrons in this process. The meaning of reduction then became generalized to include all processes involving a gain of electrons. Reducing equivalent refers to chemical species which transfer the equivalent of one electron in redox reactions. The term is common in biochemistry . A reducing equivalent can be an electron or a hydrogen atom as
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#17327649878741572-404: A late 18th century writer. Later, Grimms' dictionary (1868) noted the kobalt/kobelt ore was blamed on the mountain spirit ( Bergmännchen [ de ] ) which was also held responsible for "stealing the silver and putting out an ore that caused poor mining atmosphere ( Wetter ) and other health hazards". Grimms' dictionary entries equated the word "kobel" with "kobold", and listed it as
1703-513: A mere variant diminutive , but the latter is defined in it as a household spirit . Whereas some of the more recent commentators prefer to characterize the ore's namesake kobelt (recté kobel ) as a gnome . The early 20th century Oxford English Dictionary (1st edition, 1908) had upheld Grimm's etymology. However, by around the same time in Germany, the alternate etymology not endorsed by Grimm ( kob/kof "house, chamber" + walt "power, ruler")
1834-459: A more easily corroded " sacrificial anode " to act as the anode . The sacrificial metal, instead of the protected metal, then corrodes. A common application of cathodic protection is in galvanized steel, in which a sacrificial zinc coating on steel parts protects them from rust. Oxidation is used in a wide variety of industries, such as in the production of cleaning products and oxidizing ammonia to produce nitric acid . Redox reactions are
1965-500: 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
2096-483: 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)
2227-413: A redox reaction that takes place in a cell, the potential difference is: However, the potential of the reaction at the anode is sometimes expressed as an oxidation potential : The oxidation potential is a measure of the tendency of the reducing agent to be oxidized but does not represent the physical potential at an electrode. With this notation, the cell voltage equation is written with a plus sign In
2358-456: 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
2489-446: A transition metal-alkyl complex that is notable for its resistance to β-hydrogen elimination , in accord with Bredt's rule . The cobalt(III) and cobalt(V) complexes [Li(THF) 4 ] [Co(1-norb) 4 ] and [Co(1-norb) 4 ] [BF 4 ] are also known. Co is the only stable cobalt isotope and the only isotope that exists naturally on Earth. Twenty-two radioisotopes have been characterized:
2620-474: 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
2751-408: A whole reaction. In electrochemical reactions the oxidation and reduction processes do occur simultaneously but are separated in space. Oxidation originally implied a reaction with oxygen to form an oxide. Later, the term was expanded to encompass substances that accomplished chemical reactions similar to those of oxygen. Ultimately, the meaning was generalized to include all processes involving
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#17327649878742882-555: A wide variety of coordination complexes with ammonia and amines, which are called ammine complexes . Examples include [Co(NH 3 ) 6 ] , [Co(NH 3 ) 5 Cl] ( chloropentamminecobalt(III) ), and cis - and trans - [Co(NH 3 ) 4 Cl 2 ] . The corresponding ethylenediamine complexes are also well known. Analogues are known where the halides are replaced by nitrite , hydroxide , carbonate , etc. Alfred Werner worked extensively on these complexes in his Nobel-prize winning work. The robustness of these complexes
3013-526: Is +2 (cobalt(II)). These salts form the pink-colored metal aquo complex [Co(H 2 O) 6 ] in water. Addition of chloride gives the intensely blue [CoCl 4 ] . In a borax bead flame test , cobalt shows deep blue in both oxidizing and reducing flames. Several oxides of cobalt are known. Green cobalt(II) oxide (CoO) has rocksalt structure. It is readily oxidized with water and oxygen to brown cobalt(III) hydroxide (Co(OH) 3 ). At temperatures of 600–700 °C, CoO oxidizes to
3144-404: 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
3275-606: 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
3406-423: Is a commercially important radioisotope, used as a radioactive tracer and for the production of high-energy gamma rays . Cobalt is also used in the petroleum industry as a catalyst when refining crude oil. This is to purge it of sulfur, which is very polluting when burned and causes acid rain. Cobalt is the active center of a group of coenzymes called cobalamins . Vitamin B 12 , the best-known example of
3537-406: 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
3668-408: Is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. The oxidation and reduction processes occur simultaneously in the chemical reaction. There are two classes of redox reactions: "Redox" is a portmanteau of
3799-429: Is also called an electron acceptor . Oxidants are usually chemical substances with elements in high oxidation states (e.g., N 2 O 4 , MnO 4 , CrO 3 , Cr 2 O 7 , OsO 4 ), or else highly electronegative elements (e.g. O 2 , F 2 , Cl 2 , Br 2 , I 2 ) that can gain extra electrons by oxidizing another substance. Oxidizers are oxidants, but
3930-447: Is also known as its reduction potential ( E red ), or potential when the half-reaction takes place at a cathode. The reduction potential is a measure of the tendency of the oxidizing agent to be reduced. Its value is zero for H + e → 1 ⁄ 2 H 2 by definition, positive for oxidizing agents stronger than H (e.g., +2.866 V for F 2 ) and negative for oxidizing agents that are weaker than H (e.g., −0.763V for Zn ). For
4061-812: 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
Cobalt - Misplaced Pages Continue
4192-460: 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
4323-428: Is demonstrated by the optical resolution of tris(ethylenediamine)cobalt(III) ( [Co(en) 3 ] ). Cobalt(II) forms a wide variety of complexes, but mainly with weakly basic ligands. The pink-colored cation hexaaquocobalt(II) [Co(H 2 O) 6 ] is found in several routine cobalt salts such as the nitrate and sulfate. Upon addition of excess chloride, solutions of the hexaaquo complex converts to
4454-469: Is dependent on these ratios. Redox mechanisms also control some cellular processes. Redox proteins and their genes must be co-located for redox regulation according to the CoRR hypothesis for the function of DNA in mitochondria and chloroplasts . Wide varieties of aromatic compounds are enzymatically reduced to form free radicals that contain one more electron than their parent compounds. In general,
4585-559: Is faulted for its anachronism since nickel was not discovered until 1751. Cobalt compounds have been used for centuries to impart a rich blue color to glass , glazes , and ceramics . Cobalt has been detected in Egyptian sculpture, Persian jewelry from the third millennium BC, in the ruins of Pompeii , destroyed in 79 AD, and in China, dating from the Tang dynasty (618–907 AD) and
4716-432: Is mined as its magnetite (Fe 3 O 4 ). Titanium is mined as its dioxide, usually in the form of rutile (TiO 2 ). These oxides must be reduced to obtain the corresponding metals, often achieved by heating these oxides with carbon or carbon monoxide as reducing agents. Blast furnaces are the reactors where iron oxides and coke (a form of carbon) are combined to produce molten iron. The main chemical reaction producing
4847-457: Is much more sensitive to oxidation than ferrocene. Cobalt carbonyl ( Co 2 (CO) 8 ) is a catalyst in carbonylation and hydrosilylation reactions. Vitamin B 12 (see below ) is an organometallic compound found in nature and is the only vitamin that contains a metal atom. An example of an alkylcobalt complex in the otherwise uncommon +4 oxidation state of cobalt is the homoleptic complex tetrakis(1-norbornyl)cobalt(IV) (Co(1-norb) 4 ),
4978-540: Is not found on Earth's surface because of its tendency to react with oxygen in the atmosphere. Small amounts of cobalt compounds are found in most rocks, soils, plants, and animals. In the ocean cobalt typically reacts with chlorine. In nature, cobalt is frequently associated with nickel . Both are characteristic components of meteoric iron , though cobalt is much less abundant in iron meteorites than nickel. As with nickel, cobalt in meteoric iron alloys may have been well enough protected from oxygen and moisture to remain as
5109-505: Is not the reverse of the redox reaction in cellular respiration: Biological energy is frequently stored and released using redox reactions. Photosynthesis involves the reduction of carbon dioxide into sugars and the oxidation of water into molecular oxygen. The reverse reaction, respiration, oxidizes sugars to produce carbon dioxide and water. As intermediate steps, the reduced carbon compounds are used to reduce nicotinamide adenine dinucleotide (NAD ) to NADH, which then contributes to
5240-456: Is obtained by reducing the cobalt by-products of nickel and copper mining and smelting . Since cobalt is generally produced as a by-product, the supply of cobalt depends to a great extent on the economic feasibility of copper and nickel mining in a given market. Demand for cobalt was projected to grow 6% in 2017. Primary cobalt deposits are rare, such as those occurring in hydrothermal deposits , associated with ultramafic rocks , typified by
5371-436: 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
Cobalt - Misplaced Pages Continue
5502-417: Is one of the few simple stable cobalt(III) compounds. Cobalt(III) fluoride, which is used in some fluorination reactions, reacts vigorously with water. The inventory of complexes is very large. Starting with higher oxidation states, complexes of Co(IV) and Co(V) are rare. Examples are found in caesium hexafluorocobaltate(IV) (Cs 2 CoF 6 ) and potassium percobaltate (K 3 CoO 4 ). Cobalt(III) forms
5633-441: Is oxidized, and the oxidant or oxidizing agent gains electrons and is reduced. The pair of an oxidizing and reducing agent that is involved in a particular reaction is called a redox pair. A redox couple is a reducing species and its corresponding oxidizing form, e.g., Fe / Fe .The oxidation alone and the reduction alone are each called a half-reaction because two half-reactions always occur together to form
5764-584: Is reduced to metal by the aluminothermic reaction or reduction with carbon in a blast furnace . The United States Geological Survey estimates world reserves of cobalt at 7,100,000 metric tons. The Democratic Republic of the Congo (DRC) currently produces 63% of the world's cobalt. This market share may reach 73% by 2025 if planned expansions by mining producers like Glencore Plc take place as expected. Bloomberg New Energy Finance has estimated that by 2030, global demand for cobalt could be 47 times more than it
5895-426: 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
6026-532: 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
6157-417: 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
6288-429: 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
6419-590: 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
6550-512: The Congo in 1914, mining operations shifted again. When the Shaba conflict started in 1978, the copper mines of Katanga Province nearly stopped production. The impact on the world cobalt economy from this conflict was smaller than expected: cobalt is a rare metal, the pigment is highly toxic, and the industry had already established effective ways for recycling cobalt materials. In some cases, industry
6681-489: 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
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#17327649878746812-638: 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
6943-564: The Ming dynasty (1368–1644 AD). Cobalt has been used to color glass since the Bronze Age . The excavation of the Uluburun shipwreck yielded an ingot of blue glass, cast during the 14th century BC. Blue glass from Egypt was either colored with copper, iron, or cobalt. The oldest cobalt-colored glass is from the eighteenth dynasty of Egypt (1550–1292 BC). The source for the cobalt
7074-735: 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. Oxidation Redox ( / ˈ r ɛ d ɒ k s / RED -oks , / ˈ r iː d ɒ k s / REE -doks , reduction–oxidation or oxidation–reduction )
7205-423: 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
7336-673: The monoxide CoO. The metal reacts with fluorine (F 2 ) at 520 K to give CoF 3 ; with chlorine (Cl 2 ), bromine (Br 2 ) and iodine (I 2 ), producing equivalent binary halides . It does not react with hydrogen gas ( H 2 ) or nitrogen gas ( N 2 ) even when heated, but it does react with boron , carbon , phosphorus , arsenic and sulfur. At ordinary temperatures, it reacts slowly with mineral acids , and very slowly with moist, but not dry, air. Common oxidation states of cobalt include +2 and +3, although compounds with oxidation states ranging from −3 to +5 are also known. A common oxidation state for simple compounds
7467-405: 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
7598-638: 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
7729-550: The Bou-Azzer district of Morocco . At such locations, cobalt ores are mined exclusively, albeit at a lower concentration, and thus require more downstream processing for cobalt extraction. Several methods exist to separate cobalt from copper and nickel, depending on the concentration of cobalt and the exact composition of the used ore. One method is froth flotation , in which surfactants bind to ore components, leading to an enrichment of cobalt ores. Subsequent roasting converts
7860-484: The DRC alone accounted for more than 50%. Cobalt is primarily used in lithium-ion batteries , and in the manufacture of magnetic , wear-resistant and high-strength alloys . The compounds cobalt silicate and cobalt(II) aluminate (CoAl 2 O 4 , cobalt blue) give a distinctive deep blue color to glass , ceramics , inks , paints and varnishes . Cobalt occurs naturally as only one stable isotope , cobalt-59. Cobalt-60
7991-476: The Egyptians used is not known. The word cobalt is derived from the 16th century German " kobelt ", a type of ore, as aforementioned. The first attempts to smelt those ores for copper or silver failed, yielding simply powder (cobalt(II) oxide) instead. Because the primary ores of cobalt always contain arsenic, smelting the ore oxidized the arsenic into the highly toxic and volatile arsenic oxide , adding to
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#17327649878748122-487: 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
8253-530: The US. High purity cobalt was highly sought after for its use in jet engines and gas turbines. An adequate supply of the ore was found in Idaho near Blackbird canyon . Calera Mining Company started production at the site. Cobalt demand has further accelerated in the 21st century as an essential constituent of materials used in rechargeable batteries, superalloys, and catalysts. It has been argued that cobalt will be one of
8384-405: The anhydrous dichloride is blue, the hydrate is red. The reduction potential for the reaction Co + e → Co is +1.92 V, beyond that for chlorine to chloride, +1.36 V. Consequently, cobalt(III) chloride would spontaneously reduce to cobalt(II) chloride and chlorine. Because the reduction potential for fluorine to fluoride is so high, +2.87 V, cobalt(III) fluoride
8515-523: The atmosphere, weathering occurs; the sulfide minerals oxidize and form pink erythrite ("cobalt glance": Co 3 (AsO 4 ) 2 ·8H 2 O ) and spherocobaltite (CoCO 3 ). Cobalt is also a constituent of tobacco smoke . The tobacco plant readily absorbs and accumulates heavy metals like cobalt from the surrounding soil in its leaves. These are subsequently inhaled during tobacco smoking . The main ores of cobalt are cobaltite , erythrite , glaucodot and skutterudite (see above), but most cobalt
8646-487: 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,
8777-412: The black cobalt(II) sulfides , CoS 2 ( pyrite structure), Co 2 S 3 ( spinel structure ), and CoS ( nickel arsenide structure). Four dihalides of cobalt(II) are known: cobalt(II) fluoride (CoF 2 , pink), cobalt(II) chloride (CoCl 2 , blue), cobalt(II) bromide (CoBr 2 , green), cobalt(II) iodide (CoI 2 , blue-black). These halides exist in anhydrous and hydrated forms. Whereas
8908-425: The blue cobalt(II,III) oxide (Co 3 O 4 ), which has a spinel structure . Black cobalt(III) oxide (Co 2 O 3 ) is also known. Cobalt oxides are antiferromagnetic at low temperature : CoO ( Néel temperature 291 K) and Co 3 O 4 (Néel temperature: 40 K), which is analogous to magnetite (Fe 3 O 4 ), with a mixture of +2 and +3 oxidation states. The principal chalcogenides of cobalt are
9039-413: 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
9170-473: The cobalt ore may have got its name from "a type of mine spirit/demon" ( daemon metallicus ) while stating that this is "apparently" the kobold. Joseph William Mellor (1935) also stated that cobalt may derive from kobalos ( κόβαλος ), though other theories had been suggested. Several alternative etymologies that have been suggested, which may not involve a spirit (kobel or kobold) at all. Karl Müller-Fraureuth conjectured that kobelt derived from Kübel ,
9301-443: The copper sulfate solution, thus liberating free copper metal. The reaction is spontaneous and releases 213 kJ per 65 g of zinc. The ionic equation for this reaction is: As two half-reactions , it is seen that the zinc is oxidized: And the copper is reduced: A disproportionation reaction is one in which a single substance is both oxidized and reduced. For example, thiosulfate ion with sulfur in oxidation state +2 can react in
9432-479: The creation of a proton gradient , which drives the synthesis of adenosine triphosphate (ATP) and is maintained by the reduction of oxygen. In animal cells, mitochondria perform similar functions. Free radical reactions are redox reactions that occur as part of homeostasis and killing microorganisms . In these reactions, an electron detaches from a molecule and then re-attaches almost instantly. Free radicals are part of redox molecules and can become harmful to
9563-408: 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
9694-465: The deep blue CoCl 2− 4 , which is tetrahedral. Softer ligands like triphenylphosphine form complexes with Co(II) and Co(I), examples being bis- and tris(triphenylphosphine)cobalt(I) chloride, CoCl 2 (PPh 3 ) 2 and CoCl(PPh 3 ) 3 . These Co(I) and Co(II) complexes represent a link to the organometallic complexes described below. Cobaltocene is a structural analog to ferrocene , with cobalt in place of iron. Cobaltocene
9825-416: 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
9956-476: The electron donor is any of a wide variety of flavoenzymes and their coenzymes . Once formed, these anion free radicals reduce molecular oxygen to superoxide and regenerate the unchanged parent compound. The net reaction is the oxidation of the flavoenzyme's coenzymes and the reduction of molecular oxygen to form superoxide. This catalytic behavior has been described as a futile cycle or redox cycling. Minerals are generally oxidized derivatives of metals. Iron
10087-415: The electrons cancel: The protons and fluoride combine to form hydrogen fluoride in a non-redox reaction: The overall reaction is: In this type of reaction, a metal atom in a compound or solution is replaced by an atom of another metal. For example, copper is deposited when zinc metal is placed in a copper(II) sulfate solution: In the above reaction, zinc metal displaces the copper(II) ion from
10218-526: 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
10349-406: 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
10480-470: 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
10611-480: 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
10742-413: 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
10873-474: 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
11004-446: The environment. Cellular respiration , for instance, is the oxidation of glucose (C 6 H 12 O 6 ) to CO 2 and the reduction of oxygen to water . The summary equation for cellular respiration is: The process of cellular respiration also depends heavily on the reduction of NAD to NADH and the reverse reaction (the oxidation of NADH to NAD ). Photosynthesis and cellular respiration are complementary, but photosynthesis
11135-492: 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
11266-630: 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
11397-529: 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
11528-660: The foundation of electrochemical cells, which can generate electrical energy or support electrosynthesis . Metal ores often contain metals in oxidized states, such as oxides or sulfides, from which the pure metals are extracted by smelting at high temperatures in the presence of a reducing agent. The process of electroplating uses redox reactions to coat objects with a thin layer of a material, as in chrome-plated automotive parts, silver plating cutlery , galvanization and gold-plated jewelry . Many essential biological processes involve redox reactions. Before some of these processes can begin, iron must be assimilated from
11659-445: The free (but alloyed) metal. Cobalt in compound form occurs in copper and nickel minerals. It is the major metallic component that combines with sulfur and arsenic in the sulfidic cobaltite (CoAsS), safflorite (CoAs 2 ), glaucodot ( (Co,Fe)AsS ), and skutterudite (CoAs 3 ) minerals. The mineral cattierite is similar to pyrite and occurs together with vaesite in the copper deposits of Katanga Province . When it reaches
11790-431: 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
11921-415: The hcp and fcc structures is 450 °C (842 °F), but in practice the energy difference between them is so small that random intergrowth of the two is common. Cobalt is a weakly reducing metal that is protected from oxidation by a passivating oxide film. It is attacked by halogens and sulfur . Heating in oxygen produces Co 3 O 4 which loses oxygen at 900 °C (1,650 °F) to give
12052-399: 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
12183-549: 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
12314-413: The human body if they do not reattach to the redox molecule or an antioxidant . The term redox state is often used to describe the balance of GSH/GSSG , NAD /NADH and NADP /NADPH in a biological system such as a cell or organ . The redox state is reflected in the balance of several sets of metabolites (e.g., lactate and pyruvate , beta-hydroxybutyrate and acetoacetate ), whose interconversion
12445-413: The loss of electrons or the increase in the oxidation state of a chemical species. Substances that have the ability to oxidize other substances (cause them to lose electrons) are said to be oxidative or oxidizing, and are known as oxidizing agents , oxidants, or oxidizers. The oxidant removes electrons from another substance, and is thus itself reduced. Because it "accepts" electrons, the oxidizing agent
12576-441: The main objects of geopolitical competition in a world running on renewable energy and dependent on batteries, but this perspective has also been criticised for underestimating the power of economic incentives for expanded production. The stable form of cobalt is produced in supernovae through the r-process . It comprises 0.0029% of the Earth's crust . Except as recently delivered in meteoric iron, free cobalt (the native metal )
12707-492: The molten iron is: Electron transfer reactions are central to myriad processes and properties in soils, and redox potential , quantified as Eh (platinum electrode potential ( voltage ) relative to the standard hydrogen electrode) or pe (analogous to pH as -log electron activity), is a master variable, along with pH, that controls and is governed by chemical reactions and biological processes. Early theoretical research with applications to flooded soils and paddy rice production
12838-579: The most stable, Co , has a half-life of 5.2714 years; Co has a half-life of 271.8 days; Co has a half-life of 77.27 days; and Co has a half-life of 70.86 days. All the other radioactive isotopes of cobalt have half-lives shorter than 18 hours, and in most cases shorter than 1 second. This element also has 4 meta states , all of which have half-lives shorter than 15 minutes. The isotopes of cobalt range in atomic weight from 50 u (Co) to 73 u (Co). The primary decay mode for isotopes with atomic mass unit values less than that of
12969-468: The notoriety of the ore. Paracelsus , Georgius Agricola , and Basil Valentine all referred to such silicates as "cobalt". Swedish chemist Georg Brandt (1694–1768) is credited with discovering cobalt c. 1735 , showing it to be a previously unknown element, distinct from bismuth and other traditional metals. Brandt called it a new "semi-metal", naming it for the mineral from which he had extracted it. He showed that compounds of cobalt metal were
13100-414: The only stable isotope, Co, is electron capture and the primary mode of decay in isotopes with atomic mass greater than 59 atomic mass units is beta decay . The primary decay products below Co are element 26 ( iron ) isotopes; above that the decay products are element 28 (nickel) isotopes. Many different stories about the origin of the word "cobalt" have been proposed. In one version the element cobalt
13231-429: The ores to cobalt sulfate , and the copper and the iron are oxidized to the oxide. Leaching with water extracts the sulfate together with the arsenates . The residues are further leached with sulfuric acid , yielding a solution of copper sulfate. Cobalt can also be leached from the slag of copper smelting. The products of the above-mentioned processes are transformed into the cobalt oxide (Co 3 O 4 ). This oxide
13362-418: 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
13493-426: 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,
13624-404: The presence of acid to form elemental sulfur (oxidation state 0) and sulfur dioxide (oxidation state +4). Thus one sulfur atom is reduced from +2 to 0, while the other is oxidized from +2 to +4. Cathodic protection is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell . A simple method of protection connects protected metal to
13755-412: 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
13886-544: The reaction between hydrogen and fluorine , hydrogen is being oxidized and fluorine is being reduced: This spontaneous reaction releases 542 kJ per 2 g of hydrogen because the H-F bond is much stronger than the F-F bond. This reaction can be analyzed as two half-reactions . The oxidation reaction converts hydrogen to protons : The reduction reaction converts fluorine to the fluoride anion: The half-reactions are combined so that
14017-772: 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
14148-410: The reducing agent is also called an electron donor . Electron donors can also form charge transfer complexes with electron acceptors. The word reduction originally referred to the loss in weight upon heating a metallic ore such as a metal oxide to extract the metal. In other words, ore was "reduced" to metal. Antoine Lavoisier demonstrated that this loss of weight was due to the loss of oxygen as
14279-494: The reduction of carbonyl compounds to alcohols . A related method of reduction involves the use of hydrogen gas (H 2 ) as sources of H atoms. The electrochemist John Bockris proposed the words electronation and de-electronation to describe reduction and oxidation processes, respectively, when they occur at electrodes . These words are analogous to protonation and deprotonation . They have not been widely adopted by chemists worldwide, although IUPAC has recognized
14410-919: 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,
14541-495: 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
14672-404: 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
14803-457: 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
14934-545: The source of the blue color in glass, which previously had been attributed to the bismuth found with cobalt. Cobalt became the first metal to be discovered since the pre-historical period. All previously known metals (iron, copper, silver, gold, zinc, mercury, tin, lead and bismuth) had no recorded discoverers. During the 19th century, a significant part of the world's production of cobalt blue (a pigment made with cobalt compounds and alumina) and smalt ( cobalt glass powdered for use for pigment purposes in ceramics and painting)
15065-496: 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
15196-955: 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
15327-437: The term is mainly reserved for sources of oxygen, particularly in the context of explosions. Nitric acid is a strong oxidizer. Substances that have the ability to reduce other substances (cause them to gain electrons) are said to be reductive or reducing and are known as reducing agents , reductants, or reducers. The reductant transfers electrons to another substance and is thus itself oxidized. Because it donates electrons,
15458-658: The terms electronation and de-electronation. Redox reactions can occur slowly, as in the formation of rust , or rapidly, as in the case of burning fuel . Electron transfer reactions are generally fast, occurring within the time of mixing. The mechanisms of atom-transfer reactions are highly variable because many kinds of atoms can be transferred. Such reactions can also be quite complex, involving many steps. The mechanisms of electron-transfer reactions occur by two distinct pathways, inner sphere electron transfer and outer sphere electron transfer . Analysis of bond energies and ionization energies in water allows calculation of
15589-446: The thermodynamic aspects of redox reactions. Each half-reaction has a standard electrode potential ( E cell ), which is equal to the potential difference or voltage at equilibrium under standard conditions of an electrochemical cell in which the cathode reaction is the half-reaction considered, and the anode is a standard hydrogen electrode where hydrogen is oxidized: The electrode potential of each half-reaction
15720-402: The time was Georgius Agricola . He was also the oft-quoted authority on the mine spirits called " kobel " (Latinized as cobalus or pl. cobali ) in a separate work. Agricola did not make an connection between the similarly named ore and spirit. However, a causal connection (ore blamed on "kobel") was made by a contemporary, and a word origin connection (word "formed" from cobalus ) made by
15851-448: The type, is an essential vitamin for all animals. Cobalt in inorganic form is also a micronutrient for bacteria , algae , and fungi . The name cobalt derives from a type of ore considered a nuisance by 16th century German silver miners, which in turn may have been named from a spirit or goblin held superstitiously responsible for it; this spirit is considered equitable to the kobold (a household spirit ) by some, or, categorized as
15982-621: 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
16113-448: The words "REDuction" and "OXidation." The term "redox" was first used in 1928. Oxidation is a process in which a substance loses electrons. Reduction is a process in which a substance gains electrons. The processes of oxidation and reduction occur simultaneously and cannot occur independently. In redox processes, the reductant transfers electrons to the oxidant. Thus, in the reaction, the reductant or reducing agent loses electrons and
16244-528: 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,
16375-481: Was able to change to cobalt-free alternatives. In 1938, John Livingood and Glenn T. Seaborg discovered the radioisotope cobalt-60 . This isotope was famously used at Columbia University in the 1950s to establish parity violation in radioactive beta decay . After World War II, the US wanted to guarantee the supply of cobalt ore for military uses (as the Germans had been doing) and prospected for cobalt within
16506-554: Was being proposed as more convincing. Somewhat later, Paul Kretschmer (1928) explained that while this "house ruler" etymology was the proper one that backed the original meaning of kobold as household spirit, a corruption later occurred introducing the idea of "mine demon" to it. The present edition of the Etymologisches Wörterbuch (25th ed., 2012) under "kobold" lists the latter, not Grimm's etymology, but still persists, under its entry for "kobalt", that while
16637-774: Was carried out at the Norwegian Blaafarveværket . The first mines for the production of smalt in the 16th century were located in Norway, Sweden, Saxony and Hungary. With the discovery of cobalt ore in New Caledonia in 1864, the mining of cobalt in Europe declined. With the discovery of ore deposits in Ontario , Canada, in 1904 and the discovery of even larger deposits in the Katanga Province in
16768-419: Was in 2017. Chemical element A chemical element is a chemical substance whose atoms all have 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
16899-438: Was named after " kobelt ", the name which 16th century German silver miners had given to a nuisance type of ore which occurred that was corrosive and issued poisonous gas. Although such ores had been used for blue pigmentation since antiquity, the Germans at that time did not have the technology to smelt the ore into metal (cf. § History below). The authority on such kobelt ore (Latinized as cobaltum or cadmia ) at
17030-433: Was seminal for subsequent work on thermodynamic aspects of redox and plant root growth in soils. Later work built on this foundation, and expanded it for understanding redox reactions related to heavy metal oxidation state changes, pedogenesis and morphology, organic compound degradation and formation, free radical chemistry, wetland delineation, soil remediation , and various methodological approaches for characterizing
17161-569: Was ultimately named for the kobold . Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as cobaltite (CoAsS). The element is more usually produced as a by-product of copper and nickel mining. The Copperbelt in the Democratic Republic of the Congo (DRC) and Zambia yields most of the global cobalt production. World production in 2016 was 116,000 tonnes (114,000 long tons; 128,000 short tons) (according to Natural Resources Canada ), and
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