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149-481: Antimony is a chemical element ; it has symbol Sb (from Latin stibium ) and atomic number 51. A lustrous grey metal or metalloid , it is found in nature mainly as the sulfide mineral stibnite (Sb 2 S 3 ). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl . The earliest known description of this metalloid in

298-455: A = m 1 x 1 + m 2 x 2 + . . . + m N x N {\displaystyle {\overline {m}}_{a}=m_{1}x_{1}+m_{2}x_{2}+...+m_{N}x_{N}} where m 1 , m 2 , ..., m N are the atomic masses of each individual isotope, and x 1 , ..., x N are the relative abundances of these isotopes. Several applications exist that capitalize on

447-738: 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

596-540: 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

745-477: 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"

894-419: A different mass number. For example, carbon-12 , carbon-13 , and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13, and 14, respectively. The atomic number of carbon is 6, which means that every carbon atom has 6 protons so that the neutron numbers of these isotopes are 6, 7, and 8 respectively. A nuclide is a species of an atom with a specific number of protons and neutrons in

1043-505: A double pairing of 2 protons and 2 neutrons prevents any nuclides containing five ( 2 He , 3 Li ) or eight ( 4 Be ) nucleons from existing long enough to serve as platforms for the buildup of heavier elements via nuclear fusion in stars (see triple alpha process ). Only five stable nuclides contain both an odd number of protons and an odd number of neutrons. The first four "odd-odd" nuclides occur in low mass nuclides, for which changing

1192-643: 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

1341-525: 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

1490-419: A given element all have the same number of electrons and share a similar electronic structure. Because the chemical behaviour of an atom is largely determined by its electronic structure, different isotopes exhibit nearly identical chemical behaviour. The main exception to this is the kinetic isotope effect : due to their larger masses, heavier isotopes tend to react somewhat more slowly than lighter isotopes of

1639-407: A glowing patch on the plate at the point it struck. Thomson observed two separate parabolic patches of light on the photographic plate (see image), which suggested two species of nuclei with different mass-to-charge ratios. He wrote "There can, therefore, I think, be little doubt that what has been called neon is not a simple gas but a mixture of two gases, one of which has an atomic weight about 20 and

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1788-401: A layered structure ( space group R 3 m No. 166) whose layers consist of fused, ruffled, six-membered rings. The nearest and next-nearest neighbors form an irregular octahedral complex, with the three atoms in each double layer slightly closer than the three atoms in the next. This relatively close packing leads to a high density of 6.697 g/cm, but the weak bonding between the layers leads to

1937-405: A lecture by Herbert Gladstone in 1892, commented that "we only know of antimony at the present day as a highly brittle and crystalline metal, which could hardly be fashioned into a useful vase, and therefore this remarkable 'find' (artifact mentioned above) must represent the lost art of rendering antimony malleable." The British archaeologist Roger Moorey was unconvinced the artifact was indeed

2086-468: A nonoptimal number of neutrons or protons decay by beta decay (including positron emission ), electron capture , or other less common decay modes such as spontaneous fission and cluster decay . Most stable nuclides are even-proton-even-neutron, where all numbers Z , N , and A are even. The odd- A stable nuclides are divided (roughly evenly) into odd-proton-even-neutron, and even-proton-odd-neutron nuclides. Stable odd-proton-odd-neutron nuclides are

2235-427: A nucleus. As the number of protons increases, so does the ratio of neutrons to protons necessary to ensure a stable nucleus (see graph at right). For example, although the neutron:proton ratio of 2 He is 1:2, the neutron:proton ratio of 92 U is greater than 3:2. A number of lighter elements have stable nuclides with the ratio 1:1 ( Z = N ). The nuclide 20 Ca (calcium-40)

2384-500: 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

2533-483: 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)

2682-405: A product of stellar nucleosynthesis or another type of nucleosynthesis such as cosmic ray spallation , and have persisted down to the present because their rate of decay is very slow (e.g. uranium-238 and potassium-40 ). Post-primordial isotopes were created by cosmic ray bombardment as cosmogenic nuclides (e.g., tritium , carbon-14 ), or by the decay of a radioactive primordial isotope to

2831-506: A proton to a neutron or vice versa would lead to a very lopsided proton-neutron ratio ( 1 H , 3 Li , 5 B , and 7 N ; spins 1, 1, 3, 1). The only other entirely "stable" odd-odd nuclide, 73 Ta (spin 9), is thought to be the rarest of the 251 stable nuclides, and is the only primordial nuclear isomer , which has not yet been observed to decay despite experimental attempts. Many odd-odd radionuclides (such as

2980-478: A radioactive radiogenic nuclide daughter (e.g. uranium to radium ). A few isotopes are naturally synthesized as nucleogenic nuclides, by some other natural nuclear reaction , such as when neutrons from natural nuclear fission are absorbed by another atom. As discussed above, only 80 elements have any stable isotopes, and 26 of these have only one stable isotope. Thus, about two-thirds of stable elements occur naturally on Earth in multiple stable isotopes, with

3129-424: A single stable isotope (of these, 19 are so-called mononuclidic elements , having a single primordial stable isotope that dominates and fixes the atomic weight of the natural element to high precision; 3 radioactive mononuclidic elements occur as well). In total, there are 251 nuclides that have not been observed to decay. For the 80 elements that have one or more stable isotopes, the average number of stable isotopes

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3278-456: 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

3427-492: A stable (non-radioactive) element was found by J. J. Thomson in 1912 as part of his exploration into the composition of canal rays (positive ions). Thomson channelled streams of neon ions through parallel magnetic and electric fields, measured their deflection by placing a photographic plate in their path, and computed their mass to charge ratio using a method that became known as the Thomson's parabola method. Each stream created

3576-429: A thin film (thickness in nanometres); thicker samples spontaneously transform into the metallic form. It oxidizes in air and may ignite spontaneously. At 100 °C, it gradually transforms into the stable form. The supposed yellow allotrope of antimony, generated only by oxidation of stibine (SbH 3 ) at −90 °C, is also impure and not a true allotrope; above this temperature and in ambient light, it transforms into

3725-622: A total 30 + 2(9) = 48 stable odd-even isotopes. There are also five primordial long-lived radioactive odd-even isotopes, 37 Rb , 49 In , 75 Re , 63 Eu , and 83 Bi . The last two were only recently found to decay, with half-lives greater than 10 years. Actinides with odd neutron number are generally fissile (with thermal neutrons ), whereas those with even neutron number are generally not, though they are fissionable with fast neutrons . All observationally stable odd-odd nuclides have nonzero integer spin. This

3874-614: A vase, mentioning that Selimkhanov, after his analysis of the Tello object (published in 1975), "attempted to relate the metal to Transcaucasian natural antimony" (i.e. native metal) and that "the antimony objects from Transcaucasia are all small personal ornaments." This weakens the evidence for a lost art "of rendering antimony malleable". The Roman scholar Pliny the Elder described several ways of preparing antimony sulfide for medical purposes in his treatise Natural History , around 77 AD. Pliny

4023-474: 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

4172-681: Is aluminium-26 , which is not naturally found on Earth but is found in abundance on an astronomical scale. The tabulated atomic masses of elements are averages that account for the presence of multiple isotopes with different masses. Before the discovery of isotopes, empirically determined noninteger values of atomic mass confounded scientists. For example, a sample of chlorine contains 75.8% chlorine-35 and 24.2% chlorine-37 , giving an average atomic mass of 35.5 atomic mass units . According to generally accepted cosmology theory , only isotopes of hydrogen and helium, traces of some isotopes of lithium and beryllium, and perhaps some boron, were created at

4321-670: Is stibnite ( Sb 2 S 3 ). Other sulfide minerals include pyrargyrite ( Ag 3 SbS 3 ), zinkenite , jamesonite , and boulangerite . Antimony pentasulfide is non-stoichiometric , which features antimony in the +3 oxidation state and S–S bonds. Several thioantimonides are known, such as [Sb 6 S 10 ] and [Sb 8 S 13 ] . Antimony forms two series of halides : SbX 3 and SbX 5 . The trihalides SbF 3 , SbCl 3 , SbBr 3 , and SbI 3 are all molecular compounds having trigonal pyramidal molecular geometry . The trifluoride SbF 3

4470-404: 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

4619-547: Is 251/80 ≈ 3.14 isotopes per element. The proton:neutron ratio is not the only factor affecting nuclear stability. It depends also on evenness or oddness of its atomic number Z , neutron number N and, consequently, of their sum, the mass number A . Oddness of both Z and N tends to lower the nuclear binding energy , making odd nuclei, generally, less stable. This remarkable difference of nuclear binding energy between neighbouring nuclei, especially of odd- A isobars , has important consequences: unstable isotopes with

Antimony - Misplaced Pages Continue

4768-606: 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

4917-406: 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

5066-635: Is a radioactive form of carbon, whereas C and C are stable isotopes. There are about 339 naturally occurring nuclides on Earth, of which 286 are primordial nuclides , meaning that they have existed since the Solar System 's formation. Primordial nuclides include 35 nuclides with very long half-lives (over 100 million years) and 251 that are formally considered as " stable nuclides ", because they have not been observed to decay. In most cases, for obvious reasons, if an element has stable isotopes, those isotopes predominate in

5215-482: Is a scribal corruption of some Arabic form; Meyerhof derives it from ithmid ; other possibilities include athimar , the Arabic name of the metalloid, and a hypothetical as-stimmi , derived from or parallel to the Greek. The standard chemical symbol for antimony (Sb) is credited to Jöns Jakob Berzelius , who derived the abbreviation from stibium . The ancient words for antimony mostly have, as their chief meaning, kohl ,

5364-812: 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

5513-460: 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

5662-663: Is because the single unpaired neutron and unpaired proton have a larger nuclear force attraction to each other if their spins are aligned (producing a total spin of at least 1 unit), instead of anti-aligned. See deuterium for the simplest case of this nuclear behavior. Only 78 Pt , 4 Be , and 7 N have odd neutron number and are the most naturally abundant isotope of their element. Elements are composed either of one nuclide ( mononuclidic elements ), or of more than one naturally occurring isotopes. The unstable (radioactive) isotopes are either primordial or postprimordial. Primordial isotopes were

5811-725: Is consumed in flame retardants , 33% in lead–acid batteries , and 8% in plastics. Antimony is mainly used as the trioxide for flame-proofing compounds , always in combination with halogenated flame retardants except in halogen-containing polymers. The flame retarding effect of antimony trioxide is produced by the formation of halogenated antimony compounds, which react with hydrogen atoms, and probably also with oxygen atoms and OH radicals, thus inhibiting fire. Markets for these flame-retardants include children's clothing, toys, aircraft, and automobile seat covers. They are also added to polyester resins in fiberglass composites for such items as light aircraft engine covers. The resin will burn in

5960-435: Is denoted with symbols "u" (for unified atomic mass unit) or "Da" (for dalton ). The atomic masses of naturally occurring isotopes of an element determine the standard atomic weight of the element. When the element contains N isotopes, the expression below is applied for the average atomic mass m ¯ a {\displaystyle {\overline {m}}_{a}} : m ¯

6109-421: Is derived from the Greek roots isos ( ἴσος "equal") and topos ( τόπος "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table . It was coined by Scottish doctor and writer Margaret Todd in a 1913 suggestion to the British chemist Frederick Soddy , who popularized the term. The number of protons within

Antimony - Misplaced Pages Continue

6258-622: Is more common. Antimony trioxide is formed when antimony is burnt in air. In the gas phase, the molecule of the compound is Sb 4 O 6 , but it polymerizes upon condensing. Antimony pentoxide ( Sb 4 O 10 ) can be formed only by oxidation with concentrated nitric acid . Antimony also forms a mixed-valence oxide, antimony tetroxide ( Sb 2 O 4 ), which features both Sb(III) and Sb(V). Unlike oxides of phosphorus and arsenic , these oxides are amphoteric , do not form well-defined oxoacids , and react with acids to form antimony salts. Antimonous acid Sb(OH) 3

6407-628: Is observationally the heaviest stable nuclide with the same number of neutrons and protons. All stable nuclides heavier than calcium-40 contain more neutrons than protons. Of the 80 elements with a stable isotope, the largest number of stable isotopes observed for any element is ten (for the element tin ). No element has nine or eight stable isotopes. Five elements have seven stable isotopes, eight have six stable isotopes, ten have five stable isotopes, nine have four stable isotopes, five have three stable isotopes, 16 have two stable isotopes (counting 73 Ta as stable), and 26 elements have only

6556-436: 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

6705-419: Is pigments. 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

6854-413: Is possibly a loan word from Arabic or from Egyptian stm . The extraction of antimony from ores depends on the quality and composition of the ore. Most antimony is mined as the sulfide; lower-grade ores are concentrated by froth flotation , while higher-grade ores are heated to 500–600 °C, the temperature at which stibnite melts and separates from the gangue minerals. Antimony can be isolated from

7003-401: Is prepared by the reaction of Sb 2 O 3 with HF : It is Lewis acidic and readily accepts fluoride ions to form the complex anions SbF 4 and SbF 5 . Molten SbF 3 is a weak electrical conductor . The trichloride SbCl 3 is prepared by dissolving Sb 2 S 3 in hydrochloric acid : Arsenic sulfides are not readily attacked by

7152-400: Is resistant to attack by acids. The only stable allotrope of antimony under standard conditions is metallic, brittle , silver-white, and shiny. It crystallises in a trigonal cell, isomorphic with bismuth and the gray allotrope of arsenic , and is formed when molten antimony is cooled slowly. Amorphous black antimony is formed upon rapid cooling of antimony vapor, and is only stable as

7301-400: Is specified by the name of the particular element (this indicates the atomic number) followed by a hyphen and the mass number (e.g. helium-3 , helium-4 , carbon-12 , carbon-14 , uranium-235 and uranium-239 ). When a chemical symbol is used, e.g. "C" for carbon, standard notation (now known as "AZE notation" because A is the mass number , Z the atomic number , and E for element )

7450-457: Is stable in air at room temperature but, if heated, it reacts with oxygen to produce antimony trioxide , Sb 2 O 3 . Antimony is a silvery, lustrous gray metalloid with a Mohs scale hardness of 3, which is too soft to mark hard objects. Coins of antimony were issued in China's Guizhou in 1931; durability was poor, and minting was soon discontinued because of its softness and toxicity. Antimony

7599-432: Is the 63rd most abundant element in the crust. Even though this element is not abundant, it is found in more than 100 mineral species. Antimony is sometimes found natively (e.g. on Antimony Peak ), but more frequently it is found in the sulfide stibnite (Sb 2 S 3 ) which is the predominant ore mineral. Antimony compounds are often classified according to their oxidation state: Sb(III) and Sb(V). The +5 oxidation state

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7748-426: 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

7897-411: Is to indicate the mass number (number of nucleons) with a superscript at the upper left of the chemical symbol and to indicate the atomic number with a subscript at the lower left (e.g. 2 He , 2 He , 6 C , 6 C , 92 U , and 92 U ). Because the atomic number is given by the element symbol, it is common to state only

8046-532: 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

8195-534: Is uncertain, and all suggestions have some difficulty either of form or interpretation. The popular etymology , from ἀντίμοναχός anti-monachos or French antimoine , would mean "monk-killer", which is explained by the fact that many early alchemists were monks, and some antimony compounds were poisonous. Another popular etymology is the hypothetical Greek word ἀντίμόνος antimonos , "against aloneness", explained as "not found as metal", or "not found unalloyed". However, ancient Greek would more naturally express

8344-443: Is unknown, but the conjugate base sodium antimonite ( [Na 3 SbO 3 ] 4 ) forms upon fusing sodium oxide and Sb 4 O 6 . Transition metal antimonites are also known. Antimonic acid exists only as the hydrate HSb(OH) 6 , forming salts as the antimonate anion Sb(OH) 6 . When a solution containing this anion is dehydrated, the precipitate contains mixed oxides. The most important antimony ore

8493-619: Is unlikely to increase in the coming years, according to the Roskill report. No significant antimony deposits in China have been developed for about ten years, and the remaining economic reserves are being rapidly depleted. For antimony-importing regions, such as Europe and the U.S., antimony is considered to be a critical mineral for industrial manufacturing that is at risk of supply chain disruption. With global production coming mainly from China (74%), Tajikistan (8%), and Russia (4%), these sources are critical to supply. Approximately 48% of antimony

8642-417: 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

8791-429: 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

8940-585: 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

9089-469: The Big Bang , while all other nuclides were synthesized later, in stars and supernovae, and in interactions between energetic particles such as cosmic rays, and previously produced nuclides. (See nucleosynthesis for details of the various processes thought responsible for isotope production.) The respective abundances of isotopes on Earth result from the quantities formed by these processes, their spread through

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9238-444: The CNO cycle . The nuclides 3 Li and 5 B are minority isotopes of elements that are themselves rare compared to other light elements, whereas the other six isotopes make up only a tiny percentage of the natural abundance of their elements. 53 stable nuclides have an even number of protons and an odd number of neutrons. They are a minority in comparison to

9387-565: The Earth's crust was described by the Swedish scientist and local mine district engineer Anton von Swab in 1783; the type-sample was collected from the Sala Silver Mine in the Bergslagen mining district of Sala , Västmanland , Sweden. The medieval Latin form, from which the modern languages and late Byzantine Greek take their names for antimony, is antimonium . The origin of that

9536-480: 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

9685-625: 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

9834-591: 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. Isotope The term isotope

9983-413: The atom's nucleus is called its atomic number and is equal to the number of electrons in the neutral (non-ionized) atom. Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons . The number of nucleons (both protons and neutrons) in the nucleus is the atom's mass number , and each isotope of a given element has

10132-410: The binding energy of the nucleus (see mass defect ), the slight difference in mass between proton and neutron, and the mass of the electrons associated with the atom, the latter because the electron:nucleon ratio differs among isotopes. The mass number is a dimensionless quantity . The atomic mass, on the other hand, is measured using the atomic mass unit based on the mass of the carbon-12 atom. It

10281-465: The fissile 92 U . Because of their odd neutron numbers, the even-odd nuclides tend to have large neutron capture cross-sections, due to the energy that results from neutron-pairing effects. These stable even-proton odd-neutron nuclides tend to be uncommon by abundance in nature, generally because, to form and enter into primordial abundance, they must have escaped capturing neutrons to form yet other stable even-even isotopes, during both

10430-423: 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

10579-405: 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

10728-436: The residual strong force . Because protons are positively charged, they repel each other. Neutrons, which are electrically neutral, stabilize the nucleus in two ways. Their copresence pushes protons slightly apart, reducing the electrostatic repulsion between the protons, and they exert an attractive nuclear force on each other and on protons. For this reason, one or more neutrons are necessary for two or more protons to bind into

10877-421: The s-process and r-process of neutron capture, during nucleosynthesis in stars . For this reason, only 78 Pt and 4 Be are the most naturally abundant isotopes of their element. 48 stable odd-proton-even-neutron nuclides, stabilized by their paired neutrons, form most of the stable isotopes of the odd-numbered elements; the very few odd-proton-odd-neutron nuclides comprise

11026-638: 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

11175-578: The AZE notation is different from how it is written: 2 He is commonly pronounced as helium-four instead of four-two-helium, and 92 U as uranium two-thirty-five (American English) or uranium-two-three-five (British) instead of 235-92-uranium. Some isotopes/nuclides are radioactive , and are therefore referred to as radioisotopes or radionuclides , whereas others have never been observed to decay radioactively and are referred to as stable isotopes or stable nuclides . For example, C

11324-429: The Elder also made a distinction between "male" and "female" forms of antimony; the male form is probably the sulfide, while the female form, which is superior, heavier, and less friable, has been suspected to be native metallic antimony. The Greek naturalist Pedanius Dioscorides mentioned that antimony sulfide could be roasted by heating by a current of air. It is thought that this produced metallic antimony. Antimony

11473-487: 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

11622-671: The West was written in 1540 by Vannoccio Biringuccio . China is the largest producer of antimony and its compounds, with most production coming from the Xikuangshan Mine in Hunan. The industrial methods for refining antimony from stibnite are roasting followed by reduction with carbon , or direct reduction of stibnite with iron. The most common applications for metallic antimony are in alloys with lead and tin , which have improved properties for solders , bullets, and plain bearings . It improves

11771-429: The almost integral masses for the two isotopes Cl and Cl. After the discovery of the neutron by James Chadwick in 1932, the ultimate root cause for the existence of isotopes was clarified, that is, the nuclei of different isotopes for a given element have different numbers of neutrons, albeit having the same number of protons. A neutral atom has the same number of electrons as protons. Thus different isotopes of

11920-487: 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,

12069-635: The beta decay of actinium-230 forms thorium-230. The term "isotope", Greek for "at the same place", was suggested to Soddy by Margaret Todd , a Scottish physician and family friend, during a conversation in which he explained his ideas to her. He received the 1921 Nobel Prize in Chemistry in part for his work on isotopes. In 1914 T. W. Richards found variations between the atomic weight of lead from different mineral sources, attributable to variations in isotopic composition due to different radioactive origins. The first evidence for multiple isotopes of

12218-413: 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

12367-437: The crude antimony sulfide by reduction with scrap iron: The sulfide is converted to an oxide by roasting. The product is further purified by vaporizing the volatile antimony(III) oxide, which is recovered. This sublimate is often used directly for the main applications, impurities being arsenic and sulfide. Antimony is isolated from the oxide by a carbothermal reduction: The lower-grade ores are reduced in blast furnaces while

12516-408: 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

12665-416: 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

12814-457: The discovery of metallic antimony. The book Currus Triumphalis Antimonii (The Triumphal Chariot of Antimony), describing the preparation of metallic antimony, was published in Germany in 1604. It was purported to be written by a Benedictine monk, writing under the name Basilius Valentinus in the 15th century; if it were authentic, which it is not, it would predate Biringuccio. The metal antimony

12963-526: 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

13112-494: The elemental abundance found on Earth and in the Solar System. However, in the cases of three elements ( tellurium , indium , and rhenium ) the most abundant isotope found in nature is actually one (or two) extremely long-lived radioisotope(s) of the element, despite these elements having one or more stable isotopes. Theory predicts that many apparently "stable" nuclides are radioactive, with extremely long half-lives (discounting

13261-406: 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

13410-470: 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

13559-480: 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

13708-413: 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

13857-474: 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

14006-410: The even-even isotopes, which are about 3 times as numerous. Among the 41 even- Z elements that have a stable nuclide, only two elements (argon and cerium) have no even-odd stable nuclides. One element (tin) has three. There are 24 elements that have one even-odd nuclide and 13 that have two odd-even nuclides. Of 35 primordial radionuclides there exist four even-odd nuclides (see table at right), including

14155-492: 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

14304-630: 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

14453-529: 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

14602-486: The galaxy, and the rates of decay for isotopes that are unstable. After the initial coalescence of the Solar System , isotopes were redistributed according to mass, and the isotopic composition of elements varies slightly from planet to planet. This sometimes makes it possible to trace the origin of meteorites . The atomic mass ( m r ) of an isotope (nuclide) is determined mainly by its mass number (i.e. number of nucleons in its nucleus). Small corrections are due to

14751-401: The ground state of tantalum-180) with comparatively short half-lives are known. Usually, they beta-decay to their nearby even-even isobars that have paired protons and paired neutrons. Of the nine primordial odd-odd nuclides (five stable and four radioactive with long half-lives), only 7 N is the most common isotope of a common element. This is the case because it is a part of

14900-431: 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

15049-399: 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

15198-488: 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

15347-809: The higher-grade ores are reduced in reverberatory furnaces . In 2022, according to the US Geological Survey , China accounted for 54.5% of total antimony production, followed in second place by Russia with 18.2% and Tajikistan with 15.5%. Chinese production of antimony is expected to decline in the future as mines and smelters are closed down by the government as part of pollution control. Especially due to an environmental protection law having gone into effect in January 2015 and revised "Emission Standards of Pollutants for Stanum, Antimony, and Mercury" having gone into effect, hurdles for economic production are higher. Reported production of antimony in China has fallen and

15496-771: The highly unstable gas stibine , SbH 3 : Stibine can also be produced by treating Sb salts with hydride reagents such as sodium borohydride . Stibine decomposes spontaneously at room temperature. Because stibine has a positive heat of formation , it is thermodynamically unstable and thus antimony does not react with hydrogen directly. Organoantimony compounds are typically prepared by alkylation of antimony halides with Grignard reagents . A large variety of compounds are known with both Sb(III) and Sb(V) centers, including mixed chloro-organic derivatives, anions, and cations. Examples include triphenylstibine (Sb(C 6 H 5 ) 3 ) and pentaphenylantimony (Sb(C 6 H 5 ) 5 ). Antimony(III) sulfide , Sb 2 S 3 ,

15645-942: The hydrochloric acid, so this method offers a route to As-free Sb. The pentahalides SbF 5 and SbCl 5 have trigonal bipyramidal molecular geometry in the gas phase, but in the liquid phase, SbF 5 is polymeric , whereas SbCl 5 is monomeric. SbF 5 is a powerful Lewis acid used to make the superacid fluoroantimonic acid ("H 2 SbF 7 "). Oxyhalides are more common for antimony than for arsenic and phosphorus. Antimony trioxide dissolves in concentrated acid to form oxoantimonyl compounds such as SbOCl and (SbO) 2 SO 4 . Compounds in this class generally are described as derivatives of Sb. Antimony forms antimonides with metals, such as indium antimonide (InSb) and silver antimonide ( Ag 3 Sb ). The alkali metal and zinc antimonides, such as Na 3 Sb and Zn 3 Sb 2 , are more reactive. Treating these antimonides with acid produces

15794-409: The integers 20 and 22 and that neither is equal to the known molar mass (20.2) of neon gas. This is an example of Aston's whole number rule for isotopic masses, which states that large deviations of elemental molar masses from integers are primarily due to the fact that the element is a mixture of isotopes. Aston similarly showed in 1920 that the molar mass of chlorine (35.45) is a weighted average of

15943-464: The largest number of stable isotopes for an element being ten, for tin ( 50 Sn ). There are about 94 elements found naturally on Earth (up to plutonium inclusive), though some are detected only in very tiny amounts, such as plutonium-244 . Scientists estimate that the elements that occur naturally on Earth (some only as radioisotopes) occur as 339 isotopes ( nuclides ) in total. Only 251 of these naturally occurring nuclides are stable, in

16092-451: The largest sailing superyachts; to improve hardness and tensile strength of the lead keel, antimony is mixed with lead between 2% and 5% by volume. Antimony is used in antifriction alloys (such as Babbitt metal ), in bullets and lead shot , electrical cable sheathing, type metal (for example, for linotype printing machines), solder (some " lead-free " solders contain 5% Sb), in pewter , and in hardening alloys with low tin content in

16241-482: The least common. The 146 even-proton, even-neutron (EE) nuclides comprise ~58% of all stable nuclides and all have spin 0 because of pairing. There are also 24 primordial long-lived even-even nuclides. As a result, each of the 41 even-numbered elements from 2 to 82 has at least one stable isotope , and most of these elements have several primordial isotopes. Half of these even-numbered elements have six or more stable isotopes. The extreme stability of helium-4 due to

16390-457: The lightest elements, whose ratio of neutron number to atomic number varies the most between isotopes, it usually has only a small effect although it matters in some circumstances (for hydrogen, the lightest element, the isotope effect is large enough to affect biology strongly). The term isotopes (originally also isotopic elements , now sometimes isotopic nuclides ) is intended to imply comparison (like synonyms or isomers ). For example,

16539-402: The longest-lived isotope), and thorium X ( Ra) are impossible to separate. Attempts to place the radioelements in the periodic table led Soddy and Kazimierz Fajans independently to propose their radioactive displacement law in 1913, to the effect that alpha decay produced an element two places to the left in the periodic table, whereas beta decay emission produced an element one place to

16688-427: The low hardness and brittleness of antimony. Antimony has two stable isotopes : Sb with a natural abundance of 57.36% and Sb with a natural abundance of 42.64%. It also has 35 radioisotopes, of which the longest-lived is Sb with a half-life of 2.75 years. In addition, 29 metastable states have been characterized. The most stable of these is Sb with a half-life of 5.76 days. Isotopes that are lighter than

16837-420: The manufacturing of organ pipes . Three other applications consume nearly all the rest of the world's supply. One application is as a stabilizer and catalyst for the production of polyethylene terephthalate . Another is as a fining agent to remove microscopic bubbles in glass, mostly for TV screens – antimony ions interact with oxygen, suppressing the tendency of the latter to form bubbles. The third application

16986-504: The mass number in the superscript and leave out the atomic number subscript (e.g. He , He , C , C , U , and U ). The letter m (for metastable) is sometimes appended after the mass number to indicate a nuclear isomer , a metastable or energetically excited nuclear state (as opposed to the lowest-energy ground state ), for example 73 Ta ( tantalum-180m ). The common pronunciation of

17135-440: The more stable black allotrope. A rare explosive form of antimony can be formed from the electrolysis of antimony trichloride , but it always contains appreciable chlorine and is not really an antimony allotrope. When scratched with a sharp implement, an exothermic reaction occurs and white fumes are given off as metallic antimony forms; when rubbed with a pestle in a mortar, a strong detonation occurs. Elemental antimony adopts

17284-424: The nucleus, for example, carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, whereas the isotope concept (grouping all atoms of each element) emphasizes chemical over nuclear. The neutron number greatly affects nuclear properties, but its effect on chemical properties is negligible for most elements. Even for

17433-521: The nuclides 6 C , 6 C , 6 C are isotopes (nuclides with the same atomic number but different mass numbers ), but 18 Ar , 19 K , 20 Ca are isobars (nuclides with the same mass number ). However, isotope is the older term and so is better known than nuclide and is still sometimes used in contexts in which nuclide might be more appropriate, such as nuclear technology and nuclear medicine . An isotope and/or nuclide

17582-417: The other about 22. The parabola due to the heavier gas is always much fainter than that due to the lighter, so that probably the heavier gas forms only a small percentage of the mixture." F. W. Aston subsequently discovered multiple stable isotopes for numerous elements using a mass spectrograph . In 1919 Aston studied neon with sufficient resolution to show that the two isotopic masses are very close to

17731-689: The other naturally occurring nuclides are radioactive but occur on Earth due to their relatively long half-lives, or else due to other means of ongoing natural production. These include the afore-mentioned cosmogenic nuclides , the nucleogenic nuclides, and any radiogenic nuclides formed by ongoing decay of a primordial radioactive nuclide, such as radon and radium from uranium. An additional ~3000 radioactive nuclides not found in nature have been created in nuclear reactors and in particle accelerators. Many short-lived nuclides not found naturally on Earth have also been observed by spectroscopic analysis, being naturally created in stars or supernovae . An example

17880-726: The others. There are 41 odd-numbered elements with Z = 1 through 81, of which 39 have stable isotopes ( technetium ( 43 Tc ) and promethium ( 61 Pm ) have no stable isotopes). Of these 39 odd Z elements, 30 elements (including hydrogen-1 where 0 neutrons is even ) have one stable odd-even isotope, and nine elements: chlorine ( 17 Cl ), potassium ( 19 K ), copper ( 29 Cu ), gallium ( 31 Ga ), bromine ( 35 Br ), silver ( 47 Ag ), antimony ( 51 Sb ), iridium ( 77 Ir ), and thallium ( 81 Tl ), have two odd-even stable isotopes each. This makes

18029-418: 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

18178-426: 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,

18327-415: The possibility of proton decay , which would make all nuclides ultimately unstable). Some stable nuclides are in theory energetically susceptible to other known forms of decay, such as alpha decay or double beta decay, but no decay products have yet been observed, and so these isotopes are said to be "observationally stable". The predicted half-lives for these nuclides often greatly exceed the estimated age of

18476-581: The presence of an externally generated flame, but will extinguish when the external flame is removed. Antimony forms a highly useful alloy with lead, increasing its hardness and mechanical strength. When casting it increases fluidity of the melt and reduces shrinkage during cooling. For most applications involving lead, varying amounts of antimony are used as alloying metal. In lead–acid batteries , this addition improves plate strength and charging characteristics. For sailboats, lead keels are used to provide righting moment, ranging from 600 lbs to over 200 tons for

18625-432: The primary exceptions). The vibrational modes of a molecule are determined by its shape and by the masses of its constituent atoms; so different isotopologues have different sets of vibrational modes. Because vibrational modes allow a molecule to absorb photons of corresponding energies, isotopologues have different optical properties in the infrared range. Atomic nuclei consist of protons and neutrons bound together by

18774-457: The properties of the various isotopes of a given element. Isotope separation is a significant technological challenge, particularly with heavy elements such as uranium or plutonium. Lighter elements such as lithium, carbon, nitrogen, and oxygen are commonly separated by gas diffusion of their compounds such as CO and NO. The separation of hydrogen and deuterium is unusual because it is based on chemical rather than physical properties, for example in

18923-412: 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

19072-498: The pure negative as α- ("not"). Edmund Oscar von Lippmann conjectured a hypothetical Greek word ανθήμόνιον anthemonion , which would mean "floret", and cites several examples of related Greek words (but not that one) which describe chemical or biological efflorescence . The early uses of antimonium include the translations, in 1050–1100, by Constantine the African of Arabic medical treatises. Several authorities believe antimonium

19221-772: 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

19370-586: The relative mass difference between isotopes is much less so that the mass-difference effects on chemistry are usually negligible. (Heavy elements also have relatively more neutrons than lighter elements, so the ratio of the nuclear mass to the collective electronic mass is slightly greater.) There is also an equilibrium isotope effect . Similarly, two molecules that differ only in the isotopes of their atoms ( isotopologues ) have identical electronic structures, and therefore almost indistinguishable physical and chemical properties (again with deuterium and tritium being

19519-919: 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,

19668-451: The right. Soddy recognized that emission of an alpha particle followed by two beta particles led to the formation of an element chemically identical to the initial element but with a mass four units lighter and with different radioactive properties. Soddy proposed that several types of atoms (differing in radioactive properties) could occupy the same place in the table. For example, the alpha-decay of uranium-235 forms thorium-231, whereas

19817-503: The rigidity of lead-alloy plates in lead–acid batteries . Antimony trioxide is a prominent additive for halogen -containing flame retardants . Antimony is used as a dopant in semiconductor devices . Antimony is a member of group 15 of the periodic table , one of the elements called pnictogens , and has an electronegativity of 2.05. In accordance with periodic trends, it is more electronegative than tin or bismuth , and less electronegative than tellurium or arsenic . Antimony

19966-495: 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

20115-441: The same element. This is most pronounced by far for protium ( H ), deuterium ( H ), and tritium ( H ), because deuterium has twice the mass of protium and tritium has three times the mass of protium. These mass differences also affect the behavior of their respective chemical bonds, by changing the center of gravity ( reduced mass ) of the atomic systems. However, for heavier elements,

20264-404: 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

20413-457: 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

20562-406: The sense of never having been observed to decay as of the present time. An additional 35 primordial nuclides (to a total of 286 primordial nuclides), are radioactive with known half-lives, but have half-lives longer than 100 million years, allowing them to exist from the beginning of the Solar System. See list of nuclides for details. All the known stable nuclides occur naturally on Earth;

20711-483: The stable Sb tend to decay by β decay , and those that are heavier tend to decay by β decay , with some exceptions. Antimony is the lightest element to have an isotope with an alpha decay branch, excluding Be and other light nuclides with beta-delayed alpha emission. The abundance of antimony in the Earth's crust is estimated at 0.2 parts per million , comparable to thallium at 0.5 ppm and silver at 0.07 ppm. It

20860-403: The sulfide of antimony. The Egyptians called antimony mśdmt or stm . The Arabic word for the substance, as opposed to the cosmetic, can appear as إثمد ithmid, athmoud, othmod , or uthmod . Littré suggests the first form, which is the earliest, derives from stimmida , an accusative for stimmi . The Greek word στίμμι (stimmi) is used by Attic tragic poets of the 5th century BC, and

21009-496: 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

21158-955: 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

21307-561: 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

21456-420: The universe, and in fact, there are also 31 known radionuclides (see primordial nuclide ) with half-lives longer than the age of the universe. Adding in the radioactive nuclides that have been created artificially, there are 3,339 currently known nuclides . These include 905 nuclides that are either stable or have half-lives longer than 60 minutes. See list of nuclides for details. The existence of isotopes

21605-528: 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,

21754-513: Was first suggested in 1913 by the radiochemist Frederick Soddy , based on studies of radioactive decay chains that indicated about 40 different species referred to as radioelements (i.e. radioactive elements) between uranium and lead, although the periodic table only allowed for 11 elements between lead and uranium inclusive. Several attempts to separate these new radioelements chemically had failed. For example, Soddy had shown in 1910 that mesothorium (later shown to be Ra), radium ( Ra,

21903-470: Was frequently described in alchemical manuscripts, including the Summa Perfectionis of Pseudo-Geber , written around the 14th century. A description of a procedure for isolating antimony is later given in the 1540 book De la pirotechnia by Vannoccio Biringuccio , predating the more famous 1556 book by Agricola , De re metallica . In this context Agricola has been often incorrectly credited with

22052-460: Was known to German chemist Andreas Libavius in 1615 who obtained it by adding iron to a molten mixture of antimony sulfide, salt and potassium tartrate . This procedure produced antimony with a crystalline or starred surface. With the advent of challenges to phlogiston theory , it was recognized that antimony is an element forming sulfides, oxides, and other compounds, as do other metals. The first discovery of naturally occurring pure antimony in

22201-463: Was recognized in predynastic Egypt as an eye cosmetic ( kohl ) as early as about 3100 BC , when the cosmetic palette was invented. An artifact, said to be part of a vase, made of antimony dating to about 3000 BC was found at Telloh , Chaldea (part of present-day Iraq ), and a copper object plated with antimony dating between 2500 BC and 2200 BC has been found in Egypt . Austen, at

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