what is the minimum number of isotopes that vanadium can have
Isotopes of vanadium


Naturally occurring vanadium (V) is composed of one stable isotope V and one radioactive isotope V with a half-life of 1.5×10 years. 24 artificial radioisotopes have been characterized (in the range of mass number between 40 and 65) with the most stable being V with a half-life of 330 days, and V with a half-life of 15.9735 days. All of the remaining radioactive isotopes have half-lives shorter than an hour, the majority of them below 10 seconds, the least stable being V with
1815915
Vanadium


passivation layer forms even at room temperature. Naturally occurring vanadium is composed of one stable isotope, V, and one radioactive isotope, V. The latter has a half-life of 1.5×10 years and a natural abundance of 0.25%. V has a nuclear spin of , which is useful for NMR spectroscopy. Twenty-four artificial radioisotopes have been characterized, ranging in mass number from 40 to 65. The most stable of these isotopes are V with a half-life of 330 days, and V with a half-life
14115953
Vanadium


of 16.0 days. The remaining radioactive isotopes have half-lives shorter than an hour, most below 10 seconds. At least four isotopes have metastable excited states. Electron capture is the main decay mode for isotopes lighter than V. For the heavier ones, the most common mode is beta decay. The electron capture reactions lead to the formation of element 22 (titanium) isotopes, while beta decay leads to element 24 (chromium) isotopes. The chemistry of vanadium is noteworthy for the accessibility of the four adjacent oxidation states 2–5
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Reference materials for stable isotope analysis


, 2011). Specpure Alfa Aesar is an isotopically well-characterized vanadium solution (Nielson "et al.", 2011). Furthermore, fractionation during chemical processing can be problematic for certain isotopic analyses, such as measuring heavy isotope ratios following column chromatography. In these cases reference materials can be calibrated for particular chemical procedures. Clumped isotopes present a distinct set of challenges for isotopic reference materials. By convention the clumped isotope composition of CO liberated from CaCO (Δ) and CH (Δ/Δ/Δ) are
8041545
Vanadium


1930s and developed commercially from the 1980s onwards. Cells use +5 and +2 formal oxidization state ions. Vanadium redox batteries are used commercially for grid energy storage. Vanadate can be used for protecting steel against rust and corrosion by conversion coating. Vanadium foil is used in cladding titanium to steel because it is compatible with both iron and titanium. The moderate thermal neutron-capture cross-section and the short half-life of the isotopes produced by neutron capture makes vanadium a suitable material for the inner structure of a fusion reactor.
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Isotopes of titanium


are less than 33 seconds, and the majority of these have half-lives that are less than half a second. The isotopes of titanium range in atomic mass from 38.01 u (Ti) to 62.99 u (Ti). The primary decay mode before the most abundant stable isotope, Ti, is β and the primary mode after is β. The primary decay products before Ti are scandium isotopes and the primary products after are vanadium isotopes. Titanium-44 is a radioactive isotope of titanium that undergoes electron capture to an excited state
1815945
Isotopes of vanadium


a half-life shorter than 55 nanoseconds, with all of the isotopes lighter than it, and none of the heavier, have unknown half-lives. In 4 isotopes, metastable excited states were found (including 2 metastable states for V), which adds up to 5 meta states. The primary decay mode before the most abundant stable isotope V is electron capture. The next most common mode is beta decay. The primary decay products before V are element 22 (titanium) isotopes and the primary products after are element
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Isotopically pure diamond


An isotopical pure diamond is a type of diamond that is composed entirely of one isotope of carbon. Isotopically pure diamonds have been manufactured from either the more common carbon isotope with mass number 12 (abbreviated as C) or the less common C isotope. Compared to natural diamonds that are composed of a mixture of C and C isotopes, isotopically pure diamonds possess improved characteristics such as increased thermal conductivity. Thermal conductivity of diamonds is at a minimum when C and C are in a ratio of 1:1 and reaches a maximum when the
20236076
Neutron diffraction


the presence of large Z atoms. The scattering length varies from isotope to isotope rather than linearly with the atomic number. An element like vanadium strongly scatters X-rays, but its nuclei hardly scatters neutrons, which is why it is often used as a container material. Non-magnetic neutron diffraction is directly sensitive to the positions of the nuclei of the atoms. The nuclei of atoms, from which neutrons scatter, are tiny. Furthermore, there is no need for an atomic form factor to describe the shape of the
12347434
Isotopes of technetium


). For a fixed number of nucleons "A", the binding energies lie on one or more parabolas, with the most stable nuclide at the bottom. One can have more than one parabola because isotopes with an even number of protons and an even number of neutrons are more stable than isotopes with an odd number of neutrons and an odd number of protons. A single beta decay then transforms one into the other. When there is only one parabola, there can be only one stable isotope lying on that parabola.
1815811
SHINE Medical Technologies


also relied on venture capital funding, having secured up to from Deerfield Management beginning in October 2014. The 2014 market for medical isotopes was estimated to be about per year. Several companies in addition to SHINE are vying for part of this market, and the need for redundancy in production will support a number suppliers beyond the minimum needed to meet current demand. The company plans to start production scale generation of isotope in 2018, having pushed the proposed start date back several times, it has secured a number of supply agreements predicated
14122074
Reference materials for stable isotope analysis


Pure and Applied Chemistry (IUPAC)). A summary list of non-traditional stable isotope systems is available here, and much of this information is derived from Brand "et al." (2014). In addition to the isotope systems listed in Table 8, ongoing research is focused on measuring the isotopic composition of barium (Allmen "et al.," 2010; Miyazaki "et al.," 2014; Nan "et al"., 2015) and vanadium (Nielson "et al."
8041544
Kinetic Isotope Effects of RuBisCO


D-arabinitol 1,5-bisphophate molecule is then hydrated and cleaved to form two molecules of 3-phosphoglycerate (3 PGA). 3 PGA is then converted into hexoses to be used in the photosynthetic organism's central metabolism. The isotopic substitutions that can occur in this reaction are for carbon, oxygen, and/or hydrogen, though currently only a significant isotope effect is seen for carbon isotope substitution. Isotopes are atoms that have the same number of protons but varying numbers of neutrons. "Lighter" isotopes (like the stable Carbon-12 isotope) have a
15197514
Geochemistry


These can be identified by their atomic number Z, which is the number of protons in the nucleus. An element can have more than one value for N, the number of neutrons in the nucleus. The sum of these is the mass number, which is roughly equal to the atomic mass. Atoms with the same atomic number but different neutron numbers are called isotopes. A given isotope is identified by a letter for the element preceded by a superscript for the mass number. For example, two common isotopes of chlorine are
18308269
Chemical element


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 the
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Isotopes of darmstadtium


). No darmstadtium atoms were obtained. A compound nucleus is a loose combination of nucleons that have not arranged themselves into nuclear shells yet. It has no internal structure and is held together only by the collision forces between the target and projectile nuclei. It is estimated that it requires around 10 s for the nucleons to arrange themselves into nuclear shells, at which point the compound nucleus becomes a nuclide, and this number is used by IUPAC as the minimum half-life a claimed isotope must have to potentially be recognised as
1816433
Environmental isotopes


numbers of neutrons and thus different masses. In a specific object, you can have a ratio between two isotopes of an element. This ratio varies slightly in the world, so in order to study isotopic ratio changes across the world, changes in isotope ratios are defined as deviations from a standard, multiplied by 1000. This unit is a "per mil". As a convention, the ratio is of the heavier isotope to the lower isotope. formula_1 ‰ These variations in isotopes can occur through many types of fractionation.
15770611
Maunder Minimum


and carbon-14 cosmogenic isotope abundance records stored in terrestrial reservoirs such as ice sheets and tree rings has been greatly aided by reconstructions of solar and heliospheric magnetic fields based on historic data on Geomagnetic storm activity, which bridge the time gap between the end of the usable cosmogenic isotope data and the start of modern spacecraft data. Other historical sunspot minima have been detected either directly or by the analysis of the cosmogenic isotopes; these include the Spörer Minimum (1450–1540), and less markedly the Dalton Minimum (1790–1820). In a 2012
16438718
Vanadium


Lithium vanadium oxide has been proposed for use as a high energy density anode for lithium ion batteries, at 745 Wh/L when paired with a lithium cobalt oxide cathode. Vanadium phosphates have been proposed as the cathode in the lithium vanadium phosphate battery, another type of lithium-ion battery. Vanadium is more important in marine environments than terrestrial. A number of species of marine algae produce vanadium bromoperoxidase as well as the closely related chloroperoxidase (which may use a heme or vanadium cofactor) and iodoperoxidases. The bromoperoxidase produces an
14115979
History of wildlife tracking technology


both towards and away from the radar. Isotope analysis is based on the principle that most elements exist in two or more forms, known as isotopes. Isotopes have the same number of protons but differ in their number of neutrons, resulting in different masses. This variation in the relative abundance of stable isotopes results from tiny mass differences that cause the isotopes to act differently in chemical reactions and physical processes. Different environments are often characterized by predictable isotopic signatures, meaning that organism's unique isotopic signatures can be traced to unique environments
13165808
Vanadium


There are two groups of vanadium steel alloys. Vanadium high-carbon steel alloys contain 0.15% to 0.25% vanadium, and high-speed tool steels (HSS) have a vanadium content of 1% to 5%. For high-speed tool steels, a hardness above HRC 60 can be achieved. HSS steel is used in surgical instruments and tools. Powder-metallurgic alloys contain up to 18% percent vanadium. The high content of vanadium carbides in those alloys increases wear resistance significantly. One application for those alloys
14115973
Transition state analog


is a measurement of the reaction rate of isotope-labeled reactants against the more common natural substrate. Kinetic isotope effect values are a ratio of the turnover number and include all steps of the reaction. Intrinsic kinetic isotope values stem from the difference in the bond vibrational environment of an atom in the reactants at ground state to the environment of the atom's transition state. Through the kinetic isotope effect much insight can be gained as to what the transition state looks like of an enzyme-catalyzed reaction and guide the development of transition
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Isotopes of hydrogen


and indeed all nuclei now believed to be stable) are only observationally stable. To date, however, experiments have shown that the minimum proton half-life is in excess of 10 years. H (atomic mass  u), the other stable hydrogen isotope, is known as "deuterium" and contains one proton and one neutron in its nucleus. The nucleus of deuterium is called a deuteron. Deuterium comprises 0.0026 – 0.0184% (by population, not by mass) of hydrogen samples on Earth, with the lower number
1561691
Mattauch isobar rule


The Mattauch isobar rule, formulated by Josef Mattauch in 1934, states that if two adjacent elements on the periodic table have isotopes of the same mass number, one of these isotopes must be radioactive. Two nuclides that have the same mass number (isobars) can both be stable only if their atomic numbers differ by more than one. In fact, for currently observationally stable nuclides, the difference can only be 2 or 4, and in theory, two nuclides that have the same mass number cannot be both stable (
18925636
Isotopically pure diamond


composition is 100% C or 100% C. The isotopes of carbon can be separated in the form of carbon dioxide gas by cascaded chemical exchange reactions with amine carbamate. Such CO can be converted to methane and from there to isotopically pure synthetic diamonds. Isotopically enriched diamonds have been synthesized by application of chemical vapor deposition followed by high pressure. The C isotopically pure, (or in practice 15-fold enrichment of isotopic number, 12 over 13 for carbon) diamond gives a 50% higher thermal conductivity than the already high value of
20236077
Mass (mass spectrometry)


isotope is not the lightest isotope. The mass spectrum peak corresponding to the monoisotopic mass is often not observed for large molecules, but can be determined from the isotopic distribution. This refers to the mass of the molecule with the most highly represented isotope distribution, based on the natural abundance of the isotopes. Isotopomers (isotopic isomers) are isomers having the same number of each isotopic atom, but differing in the positions of the isotopic atoms. For example, CHCHDCH and CHCHCHD are a pair of structural isotopomers. Isotopomers should not
4321977
Titanium


which undergoes electron capture), leading to isotopes of scandium, and the primary mode for isotopes heavier than Ti is beta emission, leading to isotopes of vanadium. Titanium becomes radioactive upon bombardment with deuterons, emitting mainly positrons and hard gamma rays. The +4 oxidation state dominates titanium chemistry, but compounds in the +3 oxidation state are also common. Commonly, titanium adopts an octahedral coordination geometry in its complexes, but tetrahedral TiCl is a notable exception. Because of its high oxidation state, titanium(IV) compounds exhibit a high degree
10740628
Vanadium pentafluoride


pentahalide of vanadium. Vanadium pentafluoride can be prepared by fluorination of vanadium metal: Alternatively, disproportionation of vanadium tetrafluoride yields equal amounts of the solid trifluoride and the volatile pentafluoride: This conversion is conducted at 650 °C. It can also be synthesized by using elemental fluorine to fluorinate industrial concentrates and raw materials so as to produce VF on an industrial scale. VF can be synthesized from the reaction of raw materials such as metallic Vanadium, ferrovanadium, vanadium (V) oxide and vanadium tetrafluoride with elemental fluorine. VF ionises in
19666577
Electron capture


Luis Alvarez, in vanadium-48. He reported it in a 1937 paper in "Physical Review". Alvarez went on to study electron capture in gallium-67 and other nuclides. Examples: The electron that is captured is one of the atom's own electrons, and not a new, incoming electron, as might be suggested by the way the above reactions are written. Radioactive isotopes that decay by pure electron capture can be inhibited from radioactive decay if they are fully ionized ("stripped" is sometimes used to describe such ions)
3727100
Mononuclidic element


(mononuclidic but not monoisotopic, since they have zero, not one, stable nuclides). A list of the 21 mononuclidic elements is given at the end of this article. Of the 26 "monoisotopic elements" that, by definition, have only one stable isotope, there exist 7 (26 minus 19 = 7) which are nevertheless "not" considered mononuclidic, due to the presence of a significant fraction of a very long-lived (primordial) radioisotope occurring in their natural abundance. These elements are vanadium,
12664846
Chemical element


atomic weight, is considered the identifying characteristic of a chemical element. The symbol for atomic number is "Z". Isotopes are atoms of the same element (that is, with the same number of protons in their atomic nucleus), but having "different" numbers of neutrons. Thus, for example, there are three main isotopes of carbon. All carbon atoms have 6 protons in the nucleus, but they can have either 6, 7, or 8 neutrons. Since the mass numbers of these are 12,
5775719
List of elements by stability of isotopes


-lives (as with ). This list depicts what is agreed upon by the consensus of the scientific community as of 2019. For each of the 80 stable elements, the number of the stable isotopes is given. Only 90 isotopes are expected to be perfectly stable, and an additional 162 are energetically unstable, but have never been observed to decay. Thus, 252 isotopes (nuclides) are stable by definition (including tantalum-180m, for which no decay has yet been observed). Those that may in the future
1663822
Kinetic isotope effect


bond weakening due to hyperconjugation in cases where a carbocation is being generated one carbon atom away (a β secondary kinetic isotope effect). These isotope effects have a theoretical maximum of "k"/"k" = 2 ≈ 1.4. For a secondary kinetic isotope effect at the α position, rehybridization from sp to sp produces a normal isotope effect, while rehybridization from sp to sp results in an inverse isotope effect with a theoretical minimum of "k"/"k" = 2 ≈ 0.7. In practice, "k"/"k" ~ 1.1-1.2 and
6941020
Kinetic isotope effect


primary kinetic isotope effects have been investigated for both the leaving groups, the nucleophiles, and the α-carbon at which the substitution occurs. Interpretation of the leaving group kinetic isotope effects had been difficult at first due to significant contributions from temperature independent factors. Kinetic isotope effects at the α-carbon can be used to develop some understanding into the symmetry of the transition state in S2 reactions, although this kinetic isotope effect is less sensitive than what would be ideal, also due to contribution from non-vibrational factors. A
6940992
Chemical element


elements have no stable isotopes and are composed "only" of radioactive isotopes: specifically the elements without any stable isotopes are technetium (atomic number 43), promethium (atomic number 61), and all observed elements with atomic numbers greater than 82. Of the 80 elements with at least one stable isotope, 26 have only one single 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 that occur for a single element is 10 (
5775722
Decay chain


radium or uranium series, and the actinium series, representing three of these four classes, and ending in three different, stable isotopes of lead. The mass number of every isotope in these chains can be represented as "A" = 4"n", "A" = 4"n" + 2, and A = 4"n" + 3, respectively. The long-lived starting isotopes of these three isotopes, respectively thorium-232, uranium-238, and uranium-235, have existed since the formation of the earth, ignoring the artificial isotopes and
19868440
Isotopes of hassium


~22 s. This figure has since been revised to 3.6 s. Hassium has been observed as decay products of darmstadtium. Darmstadtium currently has eight known isotopes, all of which have been shown to undergo alpha decays to become hassium nuclei, with mass numbers between 263 and 277. Hassium isotopes with mass numbers 266, 273, 275, and 277 to date have only been produced by darmstadtium nuclei decay. Parent darmstadtium nuclei can be themselves decay products of copernicium, flerovium, or livermorium. To date, no other elements have been known
1816402
Isotopes of darmstadtium


being discovered. Darmstadtium has been observed as a decay product of copernicium. Copernicium currently has seven known isotopes, four of which have been shown to undergo alpha decays to become darmstadtium nuclei, with mass numbers between 273 and 281. Darmstadtium isotopes with mass numbers 277, 279 and 281 to date have only been produced by copernicium nuclei decay. Parent copernicium nuclei can be themselves decay products of flerovium or livermorium. Darmstadtium may also have been produced in the electron capture decay of roentgenium nuclei which are themselves daughters of nihonium, moscovium
1816434
Isotopes of meitnerium


Laboratory (LLNL) in 1988 by bombarding einsteinium-254 with neon-22. All the isotopes of meitnerium except meitnerium-266 have been detected only in the decay chains of elements with a higher atomic number, such as roentgenium. Roentgenium currently has eight known isotopes; all but one of them undergo alpha decays to become meitnerium nuclei, with mass numbers between 268 and 282. Parent roentgenium nuclei can be themselves decay products of nihonium, flerovium, moscovium, livermorium, or tennessine. To date, no other elements have been known to decay to meitnerium
1816422
Monoisotopic element


of the long-lived radioactive primordial nuclide, are not mononuclidic. These elements are vanadium, rubidium, indium, lanthanum, europium, rhenium and lutetium. See the list below; in two noted cases (indium and rhenium), the long-lived radionuclide is actually the most abundant isotope in nature, and the stable isotope is less abundant. In 2 additional cases (bismuth and protactinium), mononuclidic elements occur primordially which are not monoisotopic because the naturally occurring nuclide is radioactive, and thus the element has no stable
6857812
Isotopes of roentgenium


the unconfirmed Rg and Rg may have longer half-lives of about 5.1 minutes and 10.7 minutes respectively. Super-heavy elements such as roentgenium are produced by bombarding lighter elements in particle accelerators that induce fusion reactions. Whereas the lightest isotope of roentgenium, roentgenium-272, can be synthesized directly this way, all the heavier roentgenium isotopes have only been observed as decay products of elements with higher atomic numbers. Depending on the energies involved, fusion reactions can be categorized as "hot" or "cold". In hot fusion reactions
1816444
Ununennium


with the increase in atomic number after curium, element 96, whose half-life is four orders of magnitude longer than that of any currently known higher-numbered element. All isotopes with an atomic number above 101 undergo radioactive decay with half-lives of less than 30 hours. No elements with atomic numbers above 82 (after lead) have stable isotopes. Nevertheless, for reasons not yet well understood, there is a slight increase of nuclear stability around atomic numbers 110–114, which leads to the appearance of what is known
18733788
Nihonium


different isotopes of nihonium have been reported with atomic masses 278, 282–287, and 290 (Nh and Nh are unconfirmed); they all decay through alpha decay to isotopes of roentgenium; there have been indications that nihonium-284 can also decay by electron capture to copernicium-284. The stability of nuclei quickly decreases with the increase in atomic number after curium, element 96, whose half-life is over ten thousand times longer than that of any subsequent element. All isotopes with an atomic number above 101 undergo radioactive decay with half-lives
1126663
Vanadium nitrogenase


Vanadium nitrogenase is a key enzyme for nitrogen fixation found in nitrogen-fixing bacteria, and is used as an alternative to molybdenum nitrogenase when molybdenum is unavailable. Vanadium nitrogenases are an important biological use of vanadium, which is uncommonly used by life. An important component of the nitrogen cycle, vanadium nitrogenase converts nitrogen gas to ammonia, thereby making otherwise inaccessible nitrogen available to plants. Unlike molybdenum nitrogenase, vanadium nitrogenase can also reduce carbon monoxide to ethylene, ethane and propane but both enzymes can reduce protons to hydrogen gas and acetylene
4568897
Transient kinetic isotope fractionation


chemical, catalytic reaction and biochemical reactions because they can describe isotopic effects in equilibrium reactions, kinetic chemical reactions and kinetic biochemical reactions. In the latter two cases, they can describe both stationary and non-stationary fractionation (i.e., variable and inverse fractionation). In general, isotopic effects depend on the number of reactants and on the number of combinations resulting from the number of substitutions in all reactants and products. Describing with accuracy isotopic effects, however, depends also on the specific rate law used to describe the chemical or
20244695
Nuclear chemistry


by the plant and not in the glucose formed in the chloroplasts within the plant cells. For biochemical and physiological experiments and medical methods, a number of specific isotopes have important applications. By organic synthesis it is possible to create a complex molecule with a radioactive label that can be confined to a small area of the molecule. For short-lived isotopes such as C, very rapid synthetic methods have been developed to permit the rapid addition of the radioactive isotope to the molecule. For instance a palladium catalysed carbonylation reaction in a
10954763
Dubnium


all elements with such high atomic numbers, it is very unstable. The longest-lasting known isotope of dubnium, Db, has a half-life of around a day. No stable isotopes have been seen, and a 2012 calculation by JINR suggested that the half-lives of all dubnium isotopes would not significantly exceed a day. Dubnium can only be obtained by artificial production. The short half-life of dubnium limits experimentation. This is exacerbated by the fact that the most stable isotopes are the hardest to synthesize.
8430310
Proton-coupled electron transfer


redox event has a minimum thermodynamics barrier associate with the first step. Similarly, the initial proton transfer (PT) mechanism has a minimum barrier associated with the protons initial pK. Variations on these minimum barriers are also considered. The important finding is that there are a number of reactions with rates greater than these minimum barriers would permit. This suggests a third mechanism lower in energy; the concerted PCET has been offered as this third mechanism. This assertion has also been supported by the observation of unusually large kinetic isotope effects (KIE
7466214
Archean life in the Barberton Greenstone Belt


be as small as about 8 μm, filamentous microfossils have diameters typically less than 5 μm and have a length that can range from tens of μm to 100 μm, and spindle-like microfossils can be as long as 50 μm. Stable isotope fractionation is a useful way of characterising organic carbon and inorganic carbon. These numbers are reported as values, where C is for the chemical element carbon. Isotope analysis of inorganic carbon typically yields δC values heavier than −10 per mil, with numbers usually falling between −5 and 5 per
5799661
Neutron scattering


. Neutron scattering and absorption cross sections vary widely from isotope to isotope. Neutron scattering can be incoherent or coherent, also depending on isotope. Among all isotopes, hydrogen has the highest scattering cross section. Important elements like carbon and oxygen are quite visible in neutron scattering—this is in marked contrast to X-ray scattering where cross sections systematically increase with atomic number. Thus neutrons can be used to analyze materials with low atomic numbers, including proteins and surfactants. This can be done at synchrotron sources but very high intensities
20361496
Isotope analysis


from different sources, limited reliable data and contamination of samples can be difficult problems in interpretation. All biologically active elements exist in a number of different isotopic forms, of which two or more are stable. For example, most carbon is present as C, with approximately 1% being C. The ratio of the two isotopes may be altered by biological and geophysical processes, and these differences can be utilized in a number of ways by ecologists. The main elements used in isotope ecology are carbon, nitrogen, oxygen, hydrogen and
9069837
Atom


stable isotopes for each of these elements, the average being 3.2 stable isotopes per element. Twenty-six elements have only a single stable isotope, while the largest number of stable isotopes observed for any element is ten, for the element tin. Elements 43, 61, and all elements numbered 83 or higher have no stable isotopes. Stability of isotopes is affected by the ratio of protons to neutrons, and also by the presence of certain "magic numbers" of neutrons or protons that represent closed and filled quantum shells.
336525
Isotopes of meitnerium


. The unconfirmed heavier Mt appears to have an even longer half-life of 67 seconds. Super-heavy elements such as meitnerium are produced by bombarding lighter elements in particle accelerators that induce fusion reactions. Whereas the lightest isotope of meitnerium, meitnerium-266, can be synthesized directly this way, all the heavier meitnerium isotopes have only been observed as decay products of elements with higher atomic numbers. Depending on the energies involved, the former are separated into "hot" and "cold". In hot fusion reactions, very light
1816417
Organovanadium chemistry


Organovanadium chemistry is the chemistry of organometallic compounds containing a carbon to vanadium (V) chemical bond. Organovanadium compounds find only minor use as reagents in organic synthesis but are significant for polymer chemistry as catalysts. Oxidation states for vanadium are +2, +3, +4 and +5. Low valency vanadium is usually stabilized with carbonyl ligands. Oxo derivatives are relatively common, unlike the organic complexes of neighboring elements. Vanadium carbonyl can be prepared by reductive carbonylation of vanadium salts: The salt can be oxidized to the 17e binary carbonyl V(CO)
16909366
Silsesquioxane


by CySiO(OH) has been proposed to approximate β-tridymite and β-cristobalite. Some of these complexes are active as catalysts for alkene metathesis, polymerization, epoxidation and Diels-Alder reactions of enones, as well as other Lewis acid-catalyzed reactions like Oppenauer oxidation and Meerwein-Pondorf-Verley reductions. . A number of metallasilsesquioxanes have been reported that can polymerize ethene, akin to the Phillips catalyst. The catalyst can be easily activated with trimethylaluminum and typically proceeds with high turnover number. Vanadium complexes as well as Ziegler
9957960
Decay chain


uranium (atomic number 92) decaying into thorium (atomic number 90). The daughter isotope may be stable or it may decay to form a daughter isotope of its own. The daughter of a daughter isotope is sometimes called a "granddaughter isotope". The time it takes for a single parent atom to decay to an atom of its daughter isotope can vary widely, not only between different parent-daughter pairs, but also randomly between identical pairings of parent and daughter isotopes. The decay of each single atom occurs spontaneously
19868424
Isotope dilution


5). On the second visit, a number of fish is captured and one observes that the ratio of native-to-labeled is 10:1. From here, we can estimate the original number of fish in the pond, "n": This is a simplified view of isotope dilution yet it illustrates the salient features of isotope dilution. A more complex situation arises when the distinction between labeled and unlabeled fish becomes fuzzy. This can occur, for example, when the lake already contains a small number of labeled fish
8542945
Virginity


widely. These social rules are referred to as sexual morality (what can and can not be done by society's rules) and sexual norms (what is and is not expected). There are a number of groups within societies promoting their views of sexual morality in a variety of ways, including through sex education, religious teachings, seeking commitments or virginity pledges, and other means. Most countries have laws which set a minimum marriage age, with the most common age being 18 years, reduced to 16 in "special
7096226
Isotopic labeling


with radium isotopes. Ra has a half-life of 11 days and can occur naturally at specific locations in rivers and groundwater sources. The isotopic ratio of radium will then decrease as the water from the source river enters a bay or estuary. By measuring the amount of Ra at a number of different locations, a circulation pattern can be deciphered. This same exact process can also be used to study the movement and discharge of groundwater. Various isotopes of lead can be used to study circulation on a global scale. Different
6645528
Isotope


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 252 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 is 252/80 = 3.15 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"
13999295
Electron


rays. The net result is a steady reduction in the number of electrons, and a matching increase in the number of neutrons. However, the process of stellar evolution can result in the synthesis of radioactive isotopes. Selected isotopes can subsequently undergo negative beta decay, emitting an electron and antineutrino from the nucleus. An example is the cobalt-60 (Co) isotope, which decays to form nickel-60 (). At the end of its lifetime, a star with more than about 20 solar masses can undergo gravitational collapse to form a
9491173
Dubnium


Elements with a lower atomic number have stable isotopes with a lower neutron-to-proton ratio than those with higher atomic number, meaning that the target and beam nuclei that could be employed to create the superheavy element have fewer neutrons than needed to form these most stable isotopes. (Different techniques based on rapid neutron capture and transfer reactions are being considered as of the 2010s, but those based on the collision of a large and small nucleus still dominate research in the area.) Only a few atoms of Db can be
8430311
Group 5 element


sea squirts) since 1911, in concentrations of vanadium in their blood more than 100 times higher than the concentration of vanadium in the seawater around them. Several species of macrofungi accumulate vanadium (up to 500 mg/kg in dry weight). Vanadium-dependent bromoperoxidase generates organobromine compounds in a number of species of marine algae. Rats and chickens are also known to require vanadium in very small amounts and deficiencies result in reduced growth and impaired reproduction. Vanadium is a relatively controversial dietary supplement, primarily for increasing insulin sensitivity and
15162895
Electron paramagnetic resonance


what dose. EPR can be used to measure microviscosity and micropolarity within drug delivery systems as well as the characterization of colloidal drug carriers. EPR/ESR spectroscopy has been used to measure properties of crude oil, in particular asphaltene and vanadium content. EPR measurement of asphaltene content is a function of spin density and solvent polarity. Prior work dating to the 1960s has demonstrated the ability to measure vanadium content to sub-ppm levels. In the field of quantum computing, pulsed EPR is used to control the state of electron spin
11991441
Vanadium


. In aqueous solution, vanadium forms metal aquo complexes of which the colours are lilac [V(HO)], green [V(HO)], blue [VO(HO)], yellow VO. Vanadium(II) compounds are reducing agents, and vanadium(V) compounds are oxidizing agents. Vanadium(IV) compounds often exist as vanadyl derivatives, which contain the VO center. Ammonium vanadate(V) (NHVO) can be successively reduced with elemental zinc to obtain the different colors of vanadium in these four oxidation states. Lower oxidation states occur in compounds such as
14115955
Vanadium


steam content of the reacting feed mixture. Another oxide of vanadium, vanadium dioxide VO, is used in the production of glass coatings, which blocks infrared radiation (and not visible light) at a specific temperature. Vanadium oxide can be used to induce color centers in corundum to create simulated alexandrite jewelry, although alexandrite in nature is a chrysoberyl. The Vanadium redox battery, a type of flow battery, is an electrochemical cell consisting of aqueous vanadium ions in different oxidation states. Batteries of the type were first proposed in the
14115977
Unbinilium


(after lead) have stable isotopes. Nevertheless, because of reasons not yet well understood, there is a slight increase of nuclear stability around atomic numbers 110–114, which leads to the appearance of what is known in nuclear physics as the "island of stability". This concept, proposed by University of California professor Glenn Seaborg, explains why superheavy elements last longer than predicted. Isotopes of unbinilium are predicted to have alpha decay half-lives of the order of microseconds. In a quantum tunneling model with mass estimates from a
18733750
Isotopic labeling


oceans (i.e. the Atlantic, Pacific, Indian, etc.) have different isotopic signatures. This results from differences in isotopic ratios of sediments and rocks within the different oceans. Because the different isotopes of lead have half-lives of 50–200 years, there is not enough time for the isotopic ratios to be homogenized throughout the whole ocean. Therefore, precise analysis of Pb isotopic ratios can be used to study the circulation of the different oceans. Isotopes with extremely long half-lives can be used to study multi-million
6645529
Bose–Einstein condensate


for up to about 1000 atoms. Various isotopes have since been condensed. In the image accompanying this article, the velocity-distribution data indicates the formation of a Bose–Einstein condensate out of a gas of rubidium atoms. The false colors indicate the number of atoms at each velocity, with red being the fewest and white being the most. The areas appearing white and light blue are at the lowest velocities. The peak is not infinitely narrow because of the Heisenberg uncertainty principle: spatially confined atoms have a minimum width velocity
4192575
Vanadium


The most important industrial vanadium compound, vanadium pentoxide, is used as a catalyst for the production of sulfuric acid. The vanadium redox battery for energy storage may be an important application in the future. Large amounts of vanadium ions are found in a few organisms, possibly as a toxin. The oxide and some other salts of vanadium have moderate toxicity. Particularly in the ocean, vanadium is used by some life forms as an active center of enzymes, such as the vanadium bromoperoxidase of some ocean algae. Vanadium was discovered by
14115946
Vanadium bromoperoxidase


Vanadium bromoperoxidases are a kind of enzymes called haloperoxidases. Its primary function is to remove hydrogen peroxide (a common cleaning agent) from in or around the cell which is produced during photosynthesis. By producing hypobromous acid (HOBr) a secondary reaction with dissolved organic matter, what results is the bromination of organic compounds that are associated with the defense of the organism. These enzymes produce the bulk of natural organobromine compounds in the world. Vanadium bromoperoxidases are one of the few classes of enzymes that requires vanadium. The active site features
7973366
Isotope


Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom. The term isotope is formed 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
13999271
Vicalloy


Vicalloy is a family of cobalt-iron-vanadium wrought permanently magnetic alloys. Vicalloy is precipitation hardened and can be formed by a number of cold working techniques. It is commonly used in electromechanical device applications, such as Wiegand wires because it shows a large Wiegand effect. It consists of 52% cobalt, 10% vanadium, trace amounts of elements such as carbon and manganese, and balance (~37%) iron. 'Vicalloy' was used in hysteresis motors both in solid and laminated form (for higher frequency applications
652611
Kinetic isotope effect


the reactants and the transition state of the isotopologues in question, and this difference can be understood qualitatively with the following description: within the Born–Oppenheimer approximation, the potential energy surface is the same for both isotopic species. However, a quantum-mechanical treatment of the energy introduces discrete vibrational levels onto this curve, and the lowest possible energy state of a molecule corresponds to the lowest vibrational energy level, which is slightly higher in energy than the minimum of the potential energy curve. This difference, referred to as the
6941010
Isotopes of francium


Francium (Fr) has no stable isotopes. A standard atomic weight cannot be given. Its most stable isotope is Fr with a half-life of 22 minutes, occurring in trace quantities as an intermediate decay product of U. Of elements whose most stable isotopes have been identified with certainty, francium is the most unstable. All elements with atomic number of greater than or equal to 106 (seaborgium) have most-stable-known isotopes shorter than that of francium, but those elements have only a relatively small number of
1600654
Solar cycle


of a century or more. The Schwabe Cycle is thought to be an amplitude modulation of the 87 year (70–100 year) Gleissberg cycle, named after Wolfgang Gleißberg. The Gleisberg cycle implied that the next solar cycle have a maximum smoothed sunspot number of about 145±30 in 2010 (instead 2010 was just after the cycle's solar minimum) and that the following cycle have a maximum of about 70±30 in 2023. Associated centennial variations in magnetic fields in the Corona and Heliosphere have been detected using Carbon-14 and beryllium-10 cosmogenic isotopes stored in
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Isotopes of technetium


When there are two parabolas, that is, when the number of nucleons is even, it can happen (rarely) that there is a stable nucleus with an odd number of neutrons and an odd number of protons (although this happens only in four instances: H, Li, B, and N). However, if this happens, there can be no stable isotope with an even number of neutrons and an even number of protons. (see beta-decay stable isobars) For technetium ("Z" =
1815812
Fluorine


transition into opaque and hard α-fluorine, which has a monoclinic structure with dense, angled layers of molecules. The transition from β- to α-fluorine is more exothermic than the condensation of fluorine, and can be violent. Only one isotope of fluorine occurs naturally in abundance, the stable isotope . It has a high magnetogyric ratio and exceptional sensitivity to magnetic fields; because it is also the only stable isotope, it is used in magnetic resonance imaging. Seventeen radioisotopes with mass numbers from 14 to 31 have been synthesized
12014427
Petroleum coke


Petroleum coke can contain vanadium, a toxic metal. Vanadium was found in the dust collected in occupied dwellings near the petroleum coke stored next to the Detroit River. Vanadium is toxic in tiny quantities, 0.8 micrograms per cubic meter of air, according to the EPA. According to multiple EPA studies and analyses, petroleum coke has a low health hazard potential in humans. It does not have any observable carcinogenic, developmental, or reproductive effects. During animal case studies repeated-dose chronic inhalation did show respiratory inflammation due to dust
4883114
Vanadium(V) oxide


shcherbinaite, is extremely rare, almost always found among fumaroles. A mineral trihydrate, VO·3HO, is also known under the name of navajoite. Upon heating a mixture of vanadium(V) oxide and vanadium(III) oxide, comproportionation occurs to give vanadium(IV) oxide, as a deep-blue solid: The reduction can also be effected by oxalic acid, carbon monoxide, and sulfur dioxide. Further reduction using hydrogen or excess CO can lead to complex mixtures of oxides such as VO and VO before black VO is reached. VO is an
10709654
Vanadyl perchlorate


Vanadyl perchlorate or vanadyl triperchlorate is a golden yellow coloured liquid or crystalline compound of vanadium, oxygen and perchlorate group. The substance consists of molecules covalently bound and is quite volatile. Vanadyl perchlorate can be made by reacting vanadium pentoxide with dichlorine heptoxide at 5°C. It is purified by distillation under a vacuum and recrystallisation at 21°C. The reaction of barium perchlorate with vanadyl sulfate solution yields a vanadyl perchlorate solution. A solution of vanadium(V) perchlorate can be made by dissolving vanadium pentoxide in perchloric acid. Pervanadyl perchlorate
1304558
Vanadium tetrafluoride


Vanadium(IV) fluoride (VF) is an inorganic compound of vanadium and fluorine. It is paramagnetic yellow-brown solid that is very hygroscopic. Unlike the corresponding vanadium tetrachloride, the tetrafluoride is not volatile because it adopts a polymeric structure. It decomposes before melting. VF can be prepared by treating VCl with HF: It was first prepared in this way. It decomposes at 325 °C, undergoing disproportionation to the tri- and pentafluorides: The structure of VF is related to that of SnF. Each vanadium centre is octahedral, surrounded
10151550
Unbiquadium


that it requires around 10 s for the nucleons to arrange themselves into nuclear shells, at which point the compound nucleus becomes a nuclide, and this number is used by IUPAC as the minimum half-life a claimed isotope must have to potentially be recognised as being discovered. Thus, the GANIL experiments do not count as a discovery of element 124. The fission of the compound nucleus 124 was also studied in 2006 at the tandem ALPI heavy-ion accelerator at the Laboratori Nazionali di Legnaro (Legnaro National Laboratories) in Italy
14533354
Extended periodic table


together only by the collision forces between the target and projectile nuclei. It is estimated that it requires around 10 s for the nucleons to arrange themselves into nuclear shells, at which point the compound nucleus becomes a nuclide, and this number is used by IUPAC as the minimum half-life a claimed isotope must have to potentially be recognised as being discovered. Thus, the GANIL experiments do not count as a discovery of element 124. The fission of the compound nucleus 124 was also studied in 2006 at the tandem ALPI heavy
19154605
Vanadyl nitrate


Vanadyl nitrate, also called vanadium oxytrinitrate or vanadium oxynitrate is a compound of vanadium in the +5 oxidation state with nitrate groups and oxygen. The formula is VO(NO). It is made from dinitrogen pentoxide and vanadium pentoxide. It is a nitrating agent, adding nitro groups to aromatic compounds such as benzene, phenol, chlorobenzene, anisole, acetanilide, benzoic acid, ethyl benzoate, and toluene. Vanadyl nitrate can be made by soaking vanadium pentoxide in liquid dinitrogen pentoxide for durations around two days at room temperature. The yield for
1114465
Vanadium nitride


Vanadium nitride, VN, is a chemical compound of vanadium and nitrogen. Vanadium nitride is formed during the nitriding of steel and increases wear resistance. Another phase, VN, also referred to as vanadium nitride, can be formed along with VN during nitriding. VN has a cubic, rock-salt structure. There is also a low-temperature form, which contains V clusters. The low-temperature phase results from a dynamic instability, when the energy of vibrational modes in the high-temperature NaCl-structure phase,
13444596
Isotope


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 that the molar mass of chlorine (35.45) is a weighted average of the almost integral masses for the two isotopes Cl and Cl. A neutral atom has the same number of electrons as protons. Thus different isotopes of a given element all have the same number of electrons and share
13999288
Isotope hydrology


or even ice ages. Another application involves the separation of groundwater flow and baseflow from streamflow in the field of catchment hydrology (i.e. a method of hydrograph separation). Since precipitation in each rain or snowfall event has a specific isotopic signature, and the signatures of subsurface water can also be identified by well sampling, the composite signature in the stream is an indicator of, at any given time, what portion of the streamflow comes from overland flow and what portion comes from subsurface flow. Stable isotopes in the water molecule are
5114681
Atomic mass


the number of protons (atomic number) from the mass number (nucleon count). The amount that the ratio of atomic masses to mass number deviates from 1 is as follows: the deviation starts positive at hydrogen-1, then decreases until it reaches a local minimum at helium-4. Isotopes of lithium, beryllium, and boron are less strongly bound than helium, as shown by their increasing mass-to-mass number ratios. At carbon, the ratio of mass (in daltons) to mass number is defined as 1,
14282176
Neutron number


(fissionable with slow neutrons) while actinides with even neutron number are usually not fissile (but are fissionable with fast neutrons). Only 58 stable have an odd neutron number, compared to 194 with an even neutron number. No odd-neutron-number isotope is the most naturally abundant isotope in its element, except for beryllium-9 which is the only stable beryllium isotope, nitrogen-14, and platinum-195. No stable nuclides have neutron number 19, 21, 35, 39, 45, 61, 89, 115, 123,
12630053
Vanadium nitrogenase


Like molybdenum nitrogenase, vanadium nitrogenase is easily oxidized and is thus only active under anaerobic conditions. Various bacteria employ complex protection mechanisms to avoid oxygen. The overall stoichiometry of nitrogen fixation catalyzed by vanadium nitrogenase can be summarized as follows: The crystal structure of "A. vinelandii" vanadium nitrogenase was resolved in 2017 (). Compared to Mo nitrogenase, V nitrogenase replaces one sulfide in the active site with a bridging ligand. Research at the University of California Irvine showed the ability of vanadium nitrogenase to convert carbon monoxide into trace amounts
4568900
Hydrogen isotope biogeochemistry


in an athlete's body, or the authenticity of foods and flavorings are all examples where chemical compounds need to be identified and sourced. Hydrogen isotopes have found uses in these and many other diverse areas of study. Since many processes can affect the D/H ratio of a given chemical compound this ratio can be a diagnostic signature for compounds produced in a specific location or via a certain process. Once the D/H ratios of a number of sources are known the measurement of this ratio for a sample of unknown origin
17293712
Paleotempestology


carbon and nitrogen isotope data have also been used to infer tropical cyclone activity. Corals can store oxygen isotope ratios which in turn reflect water temperatures, precipitation and evaporation; these in turn can be related to tropical cyclone activity. Fish otoliths and bivalves can also store such records, as can trees where the oxygen isotope ratios of precipitation are reflected in the cellulose of trees, and can be inferred with the help of tree rings. However, confounding factors like physiological isotope variations and soil properties also influence oxygen isotope ratios of tree
12891490
Lawrencium


volatility experiments. Twelve isotopes of lawrencium are known, with mass numbers 252–262 and 266; all are radioactive. Additionally, one nuclear isomer is known, with mass number 253. The longest-lived lawrencium isotope, Lr, has a half-life of ten hours and is one of the longest lived superheavy isotopes known to date, suggesting that it is perhaps on the shore of the island of stability of superheavy nuclei. However, shorter-lived isotopes are usually used in chemical experiments because Lr currently can only be produced
17864691
Evolution of metal ions in biological systems


and metal-binding proteins carry out at least one step in almost all biological pathways.Metals are also toxic so a balance must be acquired to regulate where the metals are in an organism as well as in what quantities. Many organisms have flexible systems in which they can exchange one metal for another if one is scarce. Metals in this discussion are naturally occurring elements that have a tendency to undergo oxidation. Vanadium, molybdenum, cobalt, copper, chromium, iron, manganese, nickel, and zinc are deemed essential because
11712255
Plutonium


of 24,110 years. All of the remaining radioactive isotopes have half-lives that are less than 7,000 years. This element also has eight metastable states, though all have half-lives less than one second. The known isotopes of plutonium range in mass number from 228 to 247. The primary decay modes of isotopes with mass numbers lower than the most stable isotope, plutonium-244, are spontaneous fission and alpha emission, mostly forming uranium (92 protons) and neptunium (93 protons) isotopes as decay products (neglecting the wide
19073034
Metal ions in aqueous solution


pm) for which a solvation number of 9 is well-established. Some elements in oxidation states higher than 3 form stable, aquated, oxo ions. Well known examples are the vanadyl(IV) and uranyl(VI) ions. They can be viewed as particularly stable hydrolysis products in a hypothetical reaction such as The vanadium has a distorted octahedral environment (point group C) of one oxide ion and 5 water molecules. Vanadium(V) is believed to exist as the dioxo-ion [VO(HO)] at pH less than 2, but
15640623
List of elements by stability of isotopes


only a single stable isotope, all but one have an odd atomic number — the single exception being beryllium. In addition, no odd-numbered element has more than two stable isotopes, while every even-numbered element with stable isotopes, except for helium, beryllium, and carbon, has at least three. The following tables give the elements with primordial nuclides, which means that the element may still be identified on Earth from natural sources, having been present since the Earth was formed out of the solar nebula. Thus
1663833
Geochemistry


organisms prefer lighter isotopes because there is a lower energy cost in breaking energy bonds. In addition to the previously mentioned factors, the environment and species of the organism can have a large effect on the fractionation. Through a variety of physical and chemical processes, chemical elements change in concentration and move around in what are called "geochemical cycles". An understanding of these changes requires both detailed observation and theoretical models. Each chemical compound, element or isotope has a concentration that is a function of position and time, but it
18308280
Periodic table


chemical element has a unique atomic number ("Z") representing the number of protons in its nucleus. Most elements have differing numbers of neutrons among different atoms, with these variants being referred to as isotopes. For example, carbon has three naturally occurring isotopes: all of its atoms have six protons and most have six neutrons as well, but about one per cent have seven neutrons, and a very small fraction have eight neutrons. Isotopes are never separated in the periodic table; they are always grouped together under a
3472830