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131-547: Naturally occurring lithium ( 3 Li) is composed of two stable isotopes , lithium-6 (Li) and lithium-7 (Li), with the latter being far more abundant on Earth. Both of the natural isotopes have an unexpectedly low nuclear binding energy per nucleon ( 5 332 .3312(3) keV for Li and 5 606 .4401(6) keV for Li) when compared with the adjacent lighter and heavier elements, helium ( 7 073 .9156(4) keV for helium-4) and beryllium ( 6 462 .6693(85) keV for beryllium-9). The longest-lived radioisotope of lithium

262-400: A {\displaystyle a} , and τ p {\displaystyle \tau _{\mathrm {p} }} decreases with increasing a {\displaystyle a} . Acceleration gives rise to a non-vanishing probability for the transition p → n + e + ν e . This was a matter of concern in

393-511: A diagonal relationship with magnesium , an element of similar atomic and ionic radius . Chemical resemblances between the two metals include the formation of a nitride by reaction with N 2 , the formation of an oxide ( Li 2 O ) and peroxide ( Li 2 O 2 ) when burnt in O 2 , salts with similar solubilities , and thermal instability of the carbonates and nitrides. The metal reacts with hydrogen gas at high temperatures to produce lithium hydride (LiH). Lithium forms

524-409: A magic number of 8 neutrons, Lithium-11 sits on the first of five known islands of inversion , which explains its longer half-life compared to adjacent nuclei. Lithium-12 has a considerably shorter half-life. It decays by neutron emission into Li , which decays as mentioned above. While β decay into isotopes of beryllium (often combined with single- or multiple-neutron emission)

655-404: A rhombohedral crystal system (with a nine-layer repeat spacing); at higher temperatures it transforms to face-centered cubic and then body-centered cubic . At liquid-helium temperatures (4 K) the rhombohedral structure is prevalent. Multiple allotropic forms have been identified for lithium at high pressures. Lithium has a mass specific heat capacity of 3.58 kilojoules per kilogram-kelvin,

786-427: A zinc sulfide screen produced at a distance well beyond the distance of alpha-particle range of travel but instead corresponding to the range of travel of hydrogen atoms (protons). After experimentation, Rutherford traced the reaction to the nitrogen in air and found that when alpha particles were introduced into pure nitrogen gas, the effect was larger. In 1919, Rutherford assumed that the alpha particle merely knocked

917-449: A bare nucleus, consisting of a proton (and 0 neutrons for the most abundant isotope protium 1 H ). The proton is a "bare charge" with only about 1/64,000 of the radius of a hydrogen atom, and so is extremely reactive chemically. The free proton, thus, has an extremely short lifetime in chemical systems such as liquids and it reacts immediately with the electron cloud of any available molecule. In aqueous solution, it forms

1048-593: A fairly large number of both lithium mineral and brine deposits but only comparatively few of them are of actual or potential commercial value. Many are very small, others are too low in grade." Chile is estimated (2020) to have the largest reserves by far (9.2 million tonnes), and Australia the highest annual production (40,000 tonnes). One of the largest reserve bases of lithium is in the Salar de Uyuni area of Bolivia, which has 5.4 million tonnes. Other major suppliers include Australia, Argentina and China. As of 2015,

1179-407: A flame, lithium compounds give off a striking crimson color, but when the metal burns strongly, the flame becomes a brilliant silver. Lithium will ignite and burn in oxygen when exposed to water or water vapor. In moist air, lithium rapidly tarnishes to form a black coating of lithium hydroxide (LiOH and LiOH·H 2 O), lithium nitride (Li 3 N) and lithium carbonate (Li 2 CO 3 , the result of

1310-416: A form-factor related to the two-dimensional parton diameter of the proton. A value from before 2010 is based on scattering electrons from protons followed by complex calculation involving scattering cross section based on Rosenbluth equation for momentum-transfer cross section ), and based on studies of the atomic energy levels of hydrogen and deuterium. In 2010 an international research team published

1441-438: A greater affinity than lithium-7 for the element mercury . When an amalgam of lithium and mercury is added to solutions containing lithium hydroxide , the lithium-6 becomes more concentrated in the amalgam and the lithium-7 more in the hydroxide solution. The colex ( col umn ex change) separation method makes use of this by passing a counter-flow of amalgam and hydroxide through a cascade of stages. The fraction of lithium-6

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1572-522: A higher than usual concentration of lithium (such as Centaurus X-4 ) orbit massive objects—neutron stars or black holes—whose gravity evidently pulls heavier lithium to the surface of a hydrogen-helium star, causing more lithium to be observed. On 27 May 2020, astronomers reported that classical nova explosions are galactic producers of lithium-7. Although lithium is widely distributed on Earth, it does not naturally occur in elemental form due to its high reactivity. The total lithium content of seawater

1703-644: A major source of artificial lithium fractionation, with the light isotope Li being retained by industry and military stockpiles to such an extent that it has caused slight but measurable change in the Li to Li ratios in natural sources, such as rivers. This has led to unusual uncertainty in the standardized atomic weight of lithium, since this quantity depends on the natural abundance ratios of these naturally-occurring stable lithium isotopes, as they are available in commercial lithium mineral sources. Both stable isotopes of lithium can be laser cooled and were used to produce

1834-484: A neutral hydrogen atom , which is chemically a free radical . Such "free hydrogen atoms" tend to react chemically with many other types of atoms at sufficiently low energies. When free hydrogen atoms react with each other, they form neutral hydrogen molecules (H 2 ), which are the most common molecular component of molecular clouds in interstellar space . Free protons are routinely used for accelerators for proton therapy or various particle physics experiments, with

1965-543: A number of situations in which energies or temperatures are high enough to separate them from electrons, for which they have some affinity. Free protons exist in plasmas in which temperatures are too high to allow them to combine with electrons . Free protons of high energy and velocity make up 90% of cosmic rays , which propagate through the interstellar medium . Free protons are emitted directly from atomic nuclei in some rare types of radioactive decay . Protons also result (along with electrons and antineutrinos ) from

2096-492: A potential limiting factor in this scenario, but seawater can eventually also be used. Pressurized heavy-water reactors such as the CANDU produce small quantities of tritium in their coolant/moderator from neutron absorption and this is sometimes extracted as an alternative to the use of Lithium-6. Lithium-6 is one of only four stable isotopes with a spin of 1, the others being deuterium , boron-10 , and nitrogen-14 , and has

2227-465: A proton charge radius measurement via the Lamb shift in muonic hydrogen (an exotic atom made of a proton and a negatively charged muon ). As a muon is 200 times heavier than an electron, resulting in a smaller atomic orbital , it is much more sensitive to the proton's charge radius and thus allows a more precise measurement. Subsequent improved scattering and electron-spectroscopy measurements agree with

2358-418: A proton out of nitrogen, turning it into carbon. After observing Blackett's cloud chamber images in 1925, Rutherford realized that the alpha particle was absorbed. If the alpha particle were not absorbed, then it would knock a proton off of nitrogen creating 3 charged particles (a negatively charged carbon, a proton, and an alpha particle). It can be shown that the 3 charged particles would create three tracks in

2489-697: A proton's mass. The remainder of a proton's mass is due to quantum chromodynamics binding energy , which includes the kinetic energy of the quarks and the energy of the gluon fields that bind the quarks together. The root mean square charge radius of a proton is about 0.84–0.87  fm ( 1 fm = 10  m ). In 2019, two different studies, using different techniques, found this radius to be 0.833 fm, with an uncertainty of ±0.010 fm. Free protons occur occasionally on Earth: thunderstorms can produce protons with energies of up to several tens of MeV . At sufficiently low temperatures and kinetic energies, free protons will bind to electrons . However,

2620-547: A result, they become so-called Brønsted acids . For example, a proton captured by a water molecule in water becomes hydronium , the aqueous cation H 3 O . In chemistry , the number of protons in the nucleus of an atom is known as the atomic number , which determines the chemical element to which the atom belongs. For example, the atomic number of chlorine is 17; this means that each chlorine atom has 17 protons and that all atoms with 17 protons are chlorine atoms. The chemical properties of each atom are determined by

2751-399: A scheme to generated Lithium-8 for immediate decay by bombarding stable Lithium-7 with 60 MeV protons created by a cyclotron particle accelerator . Lithium-11 is a halo nucleus consisting of a lithium-9 core surrounded by two loosely-bound neutrons; both neutrons must be present in order for this system to be bound, which has led to the description as a " Borromean nucleus ". While

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2882-421: A secondary reaction between LiOH and CO 2 ). Lithium is one of the few metals that react with nitrogen gas. Because of its reactivity with water, and especially nitrogen, lithium metal is usually stored in a hydrocarbon sealant, often petroleum jelly . Although the heavier alkali metals can be stored under mineral oil , lithium is not dense enough to fully submerge itself in these liquids. Lithium has

3013-455: A simplistic interpretation of early values of atomic weights (see Prout's hypothesis ), which was disproved when more accurate values were measured. In 1886, Eugen Goldstein discovered canal rays (also known as anode rays) and showed that they were positively charged particles (ions) produced from gases. However, since particles from different gases had different values of charge-to-mass ratio ( q / m ), they could not be identified with

3144-485: A single valence electron that, in the presence of solvents, is easily released to form Li . Because of this, lithium is a good conductor of heat and electricity as well as a highly reactive element, though it is the least reactive of the alkali metals. Lithium's lower reactivity is due to the proximity of its valence electron to its nucleus (the remaining two electrons are in the 1s orbital , much lower in energy, and do not participate in chemical bonds). Molten lithium

3275-431: A single particle, unlike the negative electrons discovered by J. J. Thomson . Wilhelm Wien in 1898 identified the hydrogen ion as the particle with the highest charge-to-mass ratio in ionized gases. Following the discovery of the atomic nucleus by Ernest Rutherford in 1911, Antonius van den Broek proposed that the place of each element in the periodic table (its atomic number) is equal to its nuclear charge. This

3406-476: A solid mineral, as opposed to potassium, which had been discovered in plant ashes, and sodium, which was known partly for its high abundance in animal blood. He named the new element "lithium". Arfwedson later showed that this same element was present in the minerals spodumene and lepidolite . In 1818, Christian Gmelin was the first to observe that lithium salts give a bright red color to flame. However, both Arfwedson and Gmelin tried and failed to isolate

3537-414: A variety of geological processes, including mineral formation (chemical precipitation and ion exchange ). Lithium ions replace magnesium or iron in certain octahedral locations in clays , and lithium-6 is sometimes preferred over Li. This results in some enrichment of Li in geological processes. In nuclear physics , Li is an important isotope, because when it is bombarded with neutrons , tritium

3668-489: A variety of binary and ternary materials by direct reaction with the main group elements. These Zintl phases , although highly covalent, can be viewed as salts of polyatomic anions such as Si 4 , P 7 , and Te 5 . With graphite, lithium forms a variety of intercalation compounds . It dissolves in ammonia (and amines) to give [Li(NH 3 ) 4 ] and the solvated electron . Lithium forms salt-like derivatives with all halides and pseudohalides. Some examples include

3799-427: A very low density (0.534 g/cm ), comparable with pine wood . It is the least dense of all elements that are solids at room temperature; the next lightest solid element (potassium, at 0.862 g/cm ) is more than 60% denser. Apart from helium and hydrogen , as a solid it is less dense than any other element as a liquid, being only two-thirds as dense as liquid nitrogen (0.808 g/cm ). Lithium can float on

3930-661: A wide variety of natural processes, including mineral formation (chemical precipitation), metabolism , and ion exchange . Lithium ions substitute for magnesium and iron in octahedral sites in clay minerals, where Li is preferred to Li, resulting in enrichment of the light isotope in processes of hyperfiltration and rock alteration. The exotic Li is known to exhibit a neutron halo , with 2 neutrons orbiting around its nucleus of 3 protons and 6 neutrons. The process known as laser isotope separation can be used to separate lithium isotopes, in particular Li from Li. Nuclear weapons manufacture and other nuclear physics applications are

4061-424: Is Li, which has a half-life of just 838.7(3)  milliseconds . Li has a half-life of 178.2(4) ms , and Li has a half-life of 8.75(6) ms . All of the remaining isotopes of lithium have half-lives that are shorter than 10 nanoseconds . The shortest-lived known isotope of lithium is Li, which decays by proton emission with a half-life of about 91(9) yoctoseconds ( 9.1(9) × 10 s ), although

Isotopes of lithium - Misplaced Pages Continue

4192-487: Is a lone proton. The nuclei of the heavy hydrogen isotopes deuterium and tritium contain one proton bound to one and two neutrons, respectively. All other types of atomic nuclei are composed of two or more protons and various numbers of neutrons. The concept of a hydrogen-like particle as a constituent of other atoms was developed over a long period. As early as 1815, William Prout proposed that all atoms are composed of hydrogen atoms (which he called "protyles"), based on

4323-510: Is a soft, silvery-white alkali metal . Under standard conditions , it is the least dense metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and flammable, and must be stored in vacuum, inert atmosphere, or inert liquid such as purified kerosene or mineral oil. It exhibits a metallic luster . It corrodes quickly in air to a dull silvery gray, then black tarnish. It does not occur freely in nature, but occurs mainly as pegmatitic minerals, which were once

4454-441: Is a unique chemical species, being a bare nucleus. As a consequence it has no independent existence in the condensed state and is invariably found bound by a pair of electrons to another atom. Ross Stewart, The Proton: Application to Organic Chemistry (1985, p. 1) In chemistry, the term proton refers to the hydrogen ion, H . Since the atomic number of hydrogen is 1, a hydrogen ion has no electrons and corresponds to

4585-418: Is about 8.0 percent. A multistage process may be used to obtain higher degrees of separation. The isotopes of lithium, in principle, can also be separated through electrochemical method and distillation chromatography, which are currently in development. Lithium-3 , also known as the triproton , would consist of three protons and zero neutrons . It was reported as proton unbound in 1969, but this result

4716-564: Is actually [BuLi] 6 and MeLi is actually [MeLi] 4 ) which feature multi-center bonding and increase the coordination number around lithium. These clusters are broken down into smaller or monomeric units in the presence of solvents like dimethoxyethane (DME) or ligands like tetramethylethylenediamine (TMEDA). As an exception to the duet rule, a two-coordinate lithate complex with four electrons around lithium, [Li(thf) 4 ] [((Me 3 Si) 3 C) 2 Li] , has been characterized crystallographically. Lithium production has greatly increased since

4847-481: Is also found in brown dwarf substellar objects and certain anomalous orange stars. Because lithium is present in cooler, less-massive brown dwarfs, but is destroyed in hotter red dwarf stars, its presence in the stars' spectra can be used in the "lithium test" to differentiate the two, as both are smaller than the Sun. Certain orange stars can also contain a high concentration of lithium. Those orange stars found to have

4978-437: Is apparently caused by the "mixing" of lithium into the interior of stars, where it is destroyed, while lithium is produced in younger stars. Although it transmutes into two atoms of helium due to collision with a proton at temperatures above 2.4 million degrees Celsius (most stars easily attain this temperature in their interiors), lithium is more abundant than computations would predict in later-generation stars. Lithium

5109-682: Is credited with reintroducing and popularizing the use of lithium to treat mania in 1949. Shortly after, throughout the mid 20th century, lithium's mood stabilizing applicability for mania and depression took off in Europe and the United States. The production and use of lithium underwent several drastic changes in history. The first major application of lithium was in high-temperature lithium greases for aircraft engines and similar applications in World War II and shortly after. This use

5240-586: Is difficult. One reason for this is that most lithium classification schemes are developed for solid ore deposits, whereas brine is a fluid that is problematic to treat with the same classification scheme due to varying concentrations and pumping effects. In 2019, world production of lithium from spodumene was around 80,000t per annum, primarily from the Greenbushes pegmatite and from some Chinese and Chilean sources. The Talison mine in Greenbushes

5371-427: Is found in trace amount in numerous plants, plankton, and invertebrates, at concentrations of 69 to 5,760 parts per billion (ppb). In vertebrates the concentration is slightly lower, and nearly all vertebrate tissue and body fluids contain lithium ranging from 21 to 763 ppb. Marine organisms tend to bioaccumulate lithium more than terrestrial organisms. Whether lithium has a physiological role in any of these organisms

Isotopes of lithium - Misplaced Pages Continue

5502-783: Is less common in the solar system than 25 of the first 32 chemical elements even though its nuclei are very light: it is an exception to the trend that heavier nuclei are less common. For related reasons, lithium has important uses in nuclear physics . The transmutation of lithium atoms to helium in 1932 was the first fully human-made nuclear reaction , and lithium deuteride serves as a fusion fuel in staged thermonuclear weapons . Lithium and its compounds have several industrial applications, including heat-resistant glass and ceramics , lithium grease lubricants, flux additives for iron, steel and aluminium production, lithium metal batteries , and lithium-ion batteries . These uses consume more than three-quarters of lithium production. Lithium

5633-480: Is not understood. Even the exact mechanisms involved in lithium toxicity are not fully understood. Petalite (LiAlSi 4 O 10 ) was discovered in 1800 by the Brazilian chemist and statesman José Bonifácio de Andrada e Silva in a mine on the island of Utö , Sweden. However, it was not until 1817 that Johan August Arfwedson , then working in the laboratory of the chemist Jöns Jakob Berzelius , detected

5764-407: Is predominant in heavier isotopes of lithium, Li and Li decay via neutron emission into Li and Li respectively due to their positions beyond the neutron drip line . Lithium-11 has also been observed to decay via multiple forms of fission. Isotopes lighter than Li decay exclusively by proton emission, as they are beyond

5895-409: Is preferentially drained by the mercury, but the lithium-7 flows mostly with the hydroxide. At the bottom of the column, the lithium (enriched with lithium-6) is separated from the amalgam, and the mercury is recovered to be reused with fresh raw material . At the top, the lithium hydroxide solution is electrolyzed to liberate the lithium-7 fraction. The enrichment obtained with this method varies with

6026-464: Is present in biological systems in trace amounts. It has no established metabolic function in humans. Lithium-based drugs are useful as a mood stabilizer and antidepressant in the treatment of mental illness such as bipolar disorder . The alkali metals are also called the lithium family, after its leading element. Like the other alkali metals (which are sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr)), lithium has

6157-489: Is produced. Both Li and Li isotopes show nuclear magnetic resonance effect, despite being quadrupolar (with nuclear spins of 1+ and 3/2−). Li has sharper lines, but due to its lower abundance requires a more sensitive NMR-spectrometer. Li is more abundant, but has broader lines because of its larger nuclear spin. The range of chemical shifts is the same of both nuclei and lies within +10 (for LiNH 2 in liquid NH 3 ) and −12 (for Li+ in fulleride ). Lithium-6 has

6288-409: Is reported to be the largest and to have the highest grade of ore at 2.4% Li 2 O (2012 figures). Proton One or more protons are present in the nucleus of every atom . They provide the attractive electrostatic central force which binds the atomic electrons. The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by

6419-512: Is reversible; neutrons can convert back to protons through beta decay , a common form of radioactive decay . In fact, a free neutron decays this way, with a mean lifetime of about 15 minutes. A proton can also transform into a neutron through beta plus decay (β+ decay). According to quantum field theory , the mean proper lifetime of protons τ p {\displaystyle \tau _{\mathrm {p} }} becomes finite when they are accelerating with proper acceleration

6550-424: Is significantly more reactive than its solid form. Lithium metal is soft enough to be cut with a knife. It is silvery-white. In air it oxidizes to lithium oxide . Its melting point of 180.50 °C (453.65 K; 356.90 °F) and its boiling point of 1,342 °C (1,615 K; 2,448 °F) are each the highest of all the alkali metals while its density of 0.534 g/cm is the lowest. Lithium has

6681-487: Is the only low numbered element that can produce net energy through nuclear fission . The two lithium nuclei have lower binding energies per nucleon than any other stable nuclides other than hydrogen-1 , deuterium and helium-3 . As a result of this, though very light in atomic weight, lithium is less common in the Solar System than 25 of the first 32 chemical elements. Seven radioisotopes have been characterized,

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6812-684: Is unknown. Lithium concentrations in human tissue averages about 24 ppb (4 ppb in blood , and 1.3 ppm in bone ). Lithium is easily absorbed by plants and lithium concentration in plant tissue is typically around 1 ppm . Some plant families bioaccumulate more lithium than others. Dry weight lithium concentrations for members of the family Solanaceae (which includes potatoes and tomatoes ), for instance, can be as high as 30 ppm while this can be as low as 0.05 ppb for corn grains . Studies of lithium concentrations in mineral-rich soil give ranges between around 0.1 and 50−100 ppm , with some concentrations as high as 100−400 ppm, although it

6943-766: Is unlikely that all of it is available for uptake by plants . Lithium accumulation does not appear to affect the essential nutrient composition of plants. Tolerance to lithium varies by plant species and typically parallels sodium tolerance ; maize and Rhodes grass , for example, are highly tolerant to lithium injury while avocado and soybean are very sensitive. Similarly, lithium at concentrations of 5 ppm reduces seed germination in some species (e.g. Asian rice and chickpea ) but not in others (e.g. barley and wheat ). Many of lithium's major biological effects can be explained by its competition with other ions. The monovalent lithium ion Li competes with other ions such as sodium (immediately below lithium on

7074-435: Is used as a part of the molten lithium fluoride in molten-salt reactors : liquid-fluoride nuclear reactors . The large neutron absorption cross section of lithium-6 (about 940 barns ) as compared with the very small neutron cross section of lithium-7 (about 45 millibarns ) makes high separation of lithium-7 from natural lithium a strong requirement for the possible use in lithium fluoride reactors. Lithium-7 hydroxide

7205-454: Is used for alkalizing of the coolant in pressurized water reactors . Some lithium-7 has been produced, for a few picoseconds, which contains a lambda particle in its nucleus, whereas an atomic nucleus is generally thought to contain only neutrons and protons. Lithium-8 has been proposed as a source of 6.4 MeV electron antineutrinos generated by the inverse beta decay to Beryllium-8. The ISODAR particle physics collaboration describes

7336-401: Is valuable as the source material for the production of tritium (hydrogen-3) and as an absorber of neutrons in nuclear fusion reactions. Between 1.9% and 7.8% of terrestrial lithium in normal materials consists of lithium-6, with the rest being lithium-7. Large amounts of lithium-6 have been separated out for placing into thermonuclear weapons . The separation of lithium-6 has by now ceased in

7467-472: Is very large and is estimated as 230 billion tonnes, where the element exists at a relatively constant concentration of 0.14 to 0.25 parts per million (ppm), or 25 micromolar ; higher concentrations approaching 7 ppm are found near hydrothermal vents . Estimates for the Earth's crustal content range from 20 to 70 ppm by weight. In keeping with its name, lithium forms a minor part of igneous rocks , with

7598-838: The Czech Geological Survey considered the entire Ore Mountains in the Czech Republic as lithium province. Five deposits are registered, one near Cínovec  [ cs ] is considered as a potentially economical deposit, with 160 000 tonnes of lithium. In December 2019, Finnish mining company Keliber Oy reported its Rapasaari lithium deposit has estimated proven and probable ore reserves of 5.280 million tonnes. In June 2010, The New York Times reported that American geologists were conducting ground surveys on dry salt lakes in western Afghanistan believing that large deposits of lithium are located there. These estimates are "based principally on old data, which

7729-587: The Morris water maze . Electrical charging of a spacecraft due to interplanetary proton bombardment has also been proposed for study. There are many more studies that pertain to space travel, including galactic cosmic rays and their possible health effects , and solar proton event exposure. The American Biostack and Soviet Biorack space travel experiments have demonstrated the severity of molecular damage induced by heavy ions on microorganisms including Artemia cysts. CPT-symmetry puts strong constraints on

7860-594: The constituent quark model, which were popular in the 1980s, and the SVZ sum rules , which allow for rough approximate mass calculations. These methods do not have the same accuracy as the more brute-force lattice QCD methods, at least not yet. The CODATA recommended value of a proton's charge radius is 8.4075(64) × 10  m . The radius of the proton is defined by a formula that can be calculated by quantum electrodynamics and be derived from either atomic spectroscopy or by electron–proton scattering. The formula involves

7991-523: The coordination complex [Li(H 2 O) 4 ] predominates for many lithium salts. Related complexes are known with amines and ethers. Organolithium compounds are numerous and useful. They are defined by the presence of a bond between carbon and lithium. They serve as metal-stabilized carbanions , although their solution and solid-state structures are more complex than this simplistic view. Thus, these are extremely powerful bases and nucleophiles . They have also been applied in asymmetric synthesis in

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8122-462: The electron cloud in a normal atom. However, in such an association with an electron, the character of the bound proton is not changed, and it remains a proton. The attraction of low-energy free protons to any electrons present in normal matter (such as the electrons in normal atoms) causes free protons to stop and to form a new chemical bond with an atom. Such a bond happens at any sufficiently "cold" temperature (that is, comparable to temperatures at

8253-766: The hydrogen nucleus (known to be the lightest nucleus) could be extracted from the nuclei of nitrogen by atomic collisions. Protons were therefore a candidate to be a fundamental or elementary particle , and hence a building block of nitrogen and all other heavier atomic nuclei. Although protons were originally considered to be elementary particles, in the modern Standard Model of particle physics , protons are known to be composite particles, containing three valence quarks , and together with neutrons are now classified as hadrons . Protons are composed of two up quarks of charge + ⁠ 2 / 3 ⁠ e each, and one down quark of charge − ⁠ 1 / 3 ⁠ e . The rest masses of quarks contribute only about 1% of

8384-414: The hydronium ion , H 3 O , which in turn is further solvated by water molecules in clusters such as [H 5 O 2 ] and [H 9 O 4 ] . The transfer of H in an acid–base reaction is usually referred to as "proton transfer". The acid is referred to as a proton donor and the base as a proton acceptor. Likewise, biochemical terms such as proton pump and proton channel refer to

8515-714: The mean lifetime of a proton for various assumed decay products. Experiments at the Super-Kamiokande detector in Japan gave lower limits for proton mean lifetime of 6.6 × 10  years for decay to an antimuon and a neutral pion , and 8.2 × 10  years for decay to a positron and a neutral pion. Another experiment at the Sudbury Neutrino Observatory in Canada searched for gamma rays resulting from residual nuclei resulting from

8646-1087: The periodic table ), which like lithium is also a monovalent alkali metal . Lithium also competes with bivalent magnesium ions, whose ionic radius (86 pm ) is approximately that of the lithium ion (90 pm). Mechanisms that transport sodium across cellular membranes also transport lithium. For instance, sodium channels (both voltage-gated and epithelial ) are particularly major pathways of entry for lithium. Lithium ions can also permeate through ligand-gated ion channels as well as cross both nuclear and mitochondrial membranes . Like sodium, lithium can enter and partially block (although not permeate ) potassium channels and calcium channels . The biological effects of lithium are many and varied but its mechanisms of action are only partially understood. For instance, studies of lithium-treated patients with bipolar disorder show that, among many other effects, lithium partially reverses telomere shortening in these patients and also increases mitochondrial function, although how lithium produces these pharmacological effects

8777-487: The radioactive decay of free neutrons , which are unstable. The spontaneous decay of free protons has never been observed, and protons are therefore considered stable particles according to the Standard Model. However, some grand unified theories (GUTs) of particle physics predict that proton decay should take place with lifetimes between 10 and 10 years. Experimental searches have established lower bounds on

8908-474: The Moon is inside the Earth's geomagnetic tail, and typically no solar wind particles were detectable. For the remainder of each lunar orbit, the Moon is in a transitional region known as the magnetosheath , where the Earth's magnetic field affects the solar wind, but does not completely exclude it. In this region, the particle flux is reduced, with typical proton velocities of 250 to 450 kilometers per second. During

9039-464: The atomic weight of lithium in some "natural sources" of lithium ion which had been "contaminated" by lithium salts discharged from isotope separation facilities, which had found its way into ground water. Lithium is used to decrease the melting temperature of glass and to improve the melting behavior of aluminium oxide in the Hall-Héroult process . These two uses dominated the market until

9170-551: The atomic weight of lithium to be around 9.8 g/mol (modern value ~6.94 g/mol). In 1855, larger quantities of lithium were produced through the electrolysis of lithium chloride by Robert Bunsen and Augustus Matthiessen . The discovery of this procedure led to commercial production of lithium in 1923 by the German company Metallgesellschaft AG , which performed an electrolysis of a liquid mixture of lithium chloride and potassium chloride . Australian psychiatrist John Cade

9301-407: The character of such bound protons does not change, and they remain protons. A fast proton moving through matter will slow by interactions with electrons and nuclei, until it is captured by the electron cloud of an atom. The result is a diatomic or polyatomic ion containing hydrogen. In a vacuum, when free electrons are present, a sufficiently slow proton may pick up a single free electron, becoming

9432-399: The cloud chamber, but instead only 2 tracks in the cloud chamber were observed. The alpha particle is absorbed by the nitrogen atom. After capture of the alpha particle, a hydrogen nucleus is ejected, creating a net result of 2 charged particles (a proton and a positively charged oxygen) which make 2 tracks in the cloud chamber. Heavy oxygen ( O), not carbon or fluorine, is the product. This was

9563-480: The coaccelerated frame there is a thermal bath due to Fulling–Davies–Unruh effect , an intrinsic effect of quantum field theory. In this thermal bath, experienced by the proton, there are electrons and antineutrinos with which the proton may interact according to the processes: Adding the contributions of each of these processes, one should obtain τ p {\displaystyle \tau _{\mathrm {p} }} . In quantum chromodynamics ,

9694-434: The column length and the flow speed. In the vacuum distillation technique, lithium is heated to a temperature of about 550  °C in a vacuum . Lithium atoms evaporate from the liquid surface and are collected on a cold surface positioned a few centimetres above the liquid surface. Since lithium-6 atoms have a greater mean free path , they are collected preferentially. The theoretical separation efficiency of this method

9825-438: The decay of a proton from oxygen-16. This experiment was designed to detect decay to any product, and established a lower limit to a proton lifetime of 2.1 × 10  years . However, protons are known to transform into neutrons through the process of electron capture (also called inverse beta decay ). For free protons, this process does not occur spontaneously but only when energy is supplied. The equation is: The process

9956-451: The end of World War II . The main sources of lithium are brines and ores . Lithium metal is produced through electrolysis applied to a mixture of fused 55% lithium chloride and 45% potassium chloride at about 450 °C. The small ionic size makes it difficult for lithium to be included in early stages of mineral crystallization. As a result, lithium remains in the molten phases, where it gets enriched, until it gets solidified in

10087-575: The final stages. Such lithium enrichment is responsible for all commercially promising lithium ore deposits. Brines (and dry salt) are another important source of Li . Although the number of known lithium-containing deposits and brines is large, most of them are either small or have too low Li concentrations. Thus, only a few appear to be of commercial value. The US Geological Survey (USGS) estimated worldwide identified lithium reserves in 2020 and 2021 to be 17 million and 21 million tonnes , respectively. An accurate estimate of world lithium reserves

10218-523: The first quantum degenerate Bose – Fermi mixture. Although it was synthesized in the Big Bang , lithium (together with beryllium and boron) is markedly less abundant in the universe than other elements. This is a result of the comparatively low stellar temperatures necessary to destroy lithium, along with a lack of common processes to produce it. According to modern cosmological theory, lithium—in both stable isotopes (lithium-6 and lithium-7)—was one of

10349-441: The first reported nuclear reaction , N + α → O + p . Rutherford at first thought of our modern "p" in this equation as a hydrogen ion, H . Depending on one's perspective, either 1919 (when it was seen experimentally as derived from another source than hydrogen) or 1920 (when it was recognized and proposed as an elementary particle) may be regarded as the moment when the proton was 'discovered'. Rutherford knew hydrogen to be

10480-418: The gluons, and transitory pairs of sea quarks . Protons have a positive charge distribution, which decays approximately exponentially, with a root mean square charge radius of about 0.8 fm. Protons and neutrons are both nucleons , which may be bound together by the nuclear force to form atomic nuclei . The nucleus of the most common isotope of the hydrogen atom (with the chemical symbol "H")

10611-453: The half-life of Li is yet to be determined, and is likely to be much shorter, like He (helium-2, diproton) which undergoes proton emission within 10 s. Both Li and Li are two of the primordial nuclides that were produced in the Big Bang , with Li to be 10 of all primordial nuclides, and Li around 10. A small percentage of Li is also known to be produced by nuclear reactions in certain stars. The isotopes of lithium separate somewhat during

10742-582: The halides LiF , LiCl , LiBr , LiI , as well as the pseudohalides and related anions. Lithium carbonate has been described as the most important compound of lithium. This white solid is the principal product of beneficiation of lithium ores. It is a precursor to other salts including ceramics and materials for lithium batteries. The compounds LiBH 4 and LiAlH 4 are useful reagents . These salts and many other lithium salts exhibit distinctively high solubility in ethers, in contrast with salts of heavier alkali metals. In aqueous solution,

10873-448: The highest of all solids. Because of this, lithium metal is often used in coolants for heat transfer applications. Naturally occurring lithium is composed of two stable isotopes , Li and Li, the latter being the more abundant (95.15% natural abundance ). Both natural isotopes have anomalously low nuclear binding energy per nucleon (compared to the neighboring elements on the periodic table , helium and beryllium ); lithium

11004-432: The large thermonuclear powers, but stockpiles of it remain in these countries. The deuterium–tritium fusion reaction has been investigated as a possible energy source, as it is currently the only fusion reaction with sufficient energy output for feasible implementation. In this scenario, lithium enriched in lithium-6 would be required to generate the necessary quantities of tritium. Mineral and brine lithium resources are

11135-400: The largest concentrations in granites . Granitic pegmatites also provide the greatest abundance of lithium-containing minerals, with spodumene and petalite being the most commercially viable sources. Another significant mineral of lithium is lepidolite which is now an obsolete name for a series formed by polylithionite and trilithionite. Another source for lithium is hectorite clay,

11266-429: The later 1990s because τ p {\displaystyle \tau _{\mathrm {p} }} is a scalar that can be measured by the inertial and coaccelerated observers . In the inertial frame , the accelerating proton should decay according to the formula above. However, according to the coaccelerated observer the proton is at rest and hence should not decay. This puzzle is solved by realizing that in

11397-482: The latter three all have heavier nuclei . The Castle Bravo thermonuclear test greatly exceeded its expected yield due to incorrect assumptions about the nuclear properties of lithium-7. The industrial production of lithium-6 results in a waste product which is enriched in lithium-7 and depleted in lithium-6. This material has been sold commercially, and some of it has been released into the environment. A relative abundance of lithium-7, as high as 35 percent greater than

11528-516: The lightest hydrocarbon oils and is one of only three metals that can float on water, the other two being sodium and potassium . Lithium's coefficient of thermal expansion is twice that of aluminium and almost four times that of iron . Lithium is superconductive below 400 μK at standard pressure and at higher temperatures (more than 9 K) at very high pressures (>20 GPa). At temperatures below 70 K, lithium, like sodium, undergoes diffusionless phase change transformations . At 4.2 K it has

11659-401: The lunar night, the spectrometer was shielded from the solar wind by the Moon and no solar wind particles were measured. Protons also have extrasolar origin from galactic cosmic rays , where they make up about 90% of the total particle flux. These protons often have higher energy than solar wind protons, and their intensity is far more uniform and less variable than protons coming from the Sun,

11790-486: The main source of lithium. Due to its solubility as an ion, it is present in ocean water and is commonly obtained from brines . Lithium metal is isolated electrolytically from a mixture of lithium chloride and potassium chloride . The nucleus of the lithium atom verges on instability, since the two stable lithium isotopes found in nature have among the lowest binding energies per nucleon of all stable nuclides . Because of its relative nuclear instability, lithium

11921-402: The mass of a quark by itself, while constituent quark mass refers to the current quark mass plus the mass of the gluon particle field surrounding the quark. These masses typically have very different values. The kinetic energy of the quarks that is a consequence of confinement is a contribution (see Mass in special relativity ). Using lattice QCD calculations, the contributions to

12052-2129: The mass of the proton are the quark condensate (~9%, comprising the up and down quarks and a sea of virtual strange quarks), the quark kinetic energy (~32%), the gluon kinetic energy (~37%), and the anomalous gluonic contribution (~23%, comprising contributions from condensates of all quark flavors). The constituent quark model wavefunction for the proton is | p ↑ ⟩ = 1 18 ( 2 | u ↑ d ↓ u ↑ ⟩ + 2 | u ↑ u ↑ d ↓ ⟩ + 2 | d ↓ u ↑ u ↑ ⟩ − | u ↑ u ↓ d ↑ ⟩ − | u ↑ d ↑ u ↓ ⟩ − | u ↓ d ↑ u ↑ ⟩ − | d ↑ u ↓ u ↑ ⟩ − | d ↑ u ↑ u ↓ ⟩ − | u ↓ u ↑ d ↑ ⟩ ) . {\displaystyle \mathrm {|p_{\uparrow }\rangle ={\tfrac {1}{\sqrt {18}}}\left(2|u_{\uparrow }d_{\downarrow }u_{\uparrow }\rangle +2|u_{\uparrow }u_{\uparrow }d_{\downarrow }\rangle +2|d_{\downarrow }u_{\uparrow }u_{\uparrow }\rangle -|u_{\uparrow }u_{\downarrow }d_{\uparrow }\rangle -|u_{\uparrow }d_{\uparrow }u_{\downarrow }\rangle -|u_{\downarrow }d_{\uparrow }u_{\uparrow }\rangle -|d_{\uparrow }u_{\downarrow }u_{\uparrow }\rangle -|d_{\uparrow }u_{\uparrow }u_{\downarrow }\rangle -|u_{\downarrow }u_{\uparrow }d_{\uparrow }\rangle \right)} .} The internal dynamics of protons are complicated, because they are determined by

12183-427: The middle of the 1990s. After the end of the nuclear arms race , the demand for lithium decreased and the sale of department of energy stockpiles on the open market further reduced prices. In the mid-1990s, several companies started to isolate lithium from brine which proved to be a less expensive option than underground or open-pit mining. Most of the mines closed or shifted their focus to other materials because only

12314-480: The modern theory of the nuclear force, most of the mass of protons and neutrons is explained by special relativity . The mass of a proton is about 80–100 times greater than the sum of the rest masses of its three valence quarks , while the gluons have zero rest mass. The extra energy of the quarks and gluons in a proton, as compared to the rest energy of the quarks alone in the QCD vacuum , accounts for almost 99% of

12445-484: The most powerful example being the Large Hadron Collider . Protons are spin- ⁠ 1 / 2 ⁠ fermions and are composed of three valence quarks, making them baryons (a sub-type of hadrons ). The two up quarks and one down quark of a proton are held together by the strong force , mediated by gluons . A modern perspective has a proton composed of the valence quarks (up, up, down),

12576-437: The most stable being Li with a half-life of 838 ms and Li with a half-life of 178 ms. All of the remaining radioactive isotopes have half-lives that are shorter than 8.6 ms. The shortest-lived isotope of lithium is Li, which decays through proton emission and has a half-life of 7.6 × 10 s. The Li isotope is one of only five stable nuclides to have both an odd number of protons and an odd number of neutrons,

12707-440: The movement of hydrated H ions. The ion produced by removing the electron from a deuterium atom is known as a deuteron , not a proton. Likewise, removing an electron from a tritium atom produces a triton . Also in chemistry, the term proton NMR refers to the observation of hydrogen-1 nuclei in (mostly organic ) molecules by nuclear magnetic resonance . This method uses the quantized spin magnetic moment of

12838-592: The natural value, has been measured in the ground water in a carbonate aquifer underneath the West Valley Creek in Pennsylvania , which is downstream from a lithium processing plant. The isotopic composition of lithium in normal materials can vary somewhat depending on its origin, which determines its relative atomic mass in the source material. An accurate relative atomic mass for samples of lithium cannot be measured for all sources of lithium. Lithium-7

12969-438: The neutral hydrogen atom. He initially suggested both proton and prouton (after Prout). Rutherford later reported that the meeting had accepted his suggestion that the hydrogen nucleus be named the "proton", following Prout's word "protyle". The first use of the word "proton" in the scientific literature appeared in 1920. One or more bound protons are present in the nucleus of every atom. Free protons are found naturally in

13100-403: The new small radius. Work continues to refine and check this new value. Since the proton is composed of quarks confined by gluons, an equivalent pressure that acts on the quarks can be defined. The size of that pressure and other details about it are controversial. In 2018 this pressure was reported to be on the order 10  Pa, which is greater than the pressure inside a neutron star . It

13231-416: The nucleon structure is still missing because ... long-distance behavior requires a nonperturbative and/or numerical treatment ..." More conceptual approaches to the structure of protons are: the topological soliton approach originally due to Tony Skyrme and the more accurate AdS/QCD approach that extends it to include a string theory of gluons, various QCD-inspired models like the bag model and

13362-598: The nucleus the proton , after the neuter singular of the Greek word for "first", πρῶτον . However, Rutherford also had in mind the word protyle as used by Prout. Rutherford spoke at the British Association for the Advancement of Science at its Cardiff meeting beginning 24 August 1920. At the meeting, he was asked by Oliver Lodge for a new name for the positive hydrogen nucleus to avoid confusion with

13493-681: The number of (negatively charged) electrons , which for neutral atoms is equal to the number of (positive) protons so that the total charge is zero. For example, a neutral chlorine atom has 17 protons and 17 electrons, whereas a Cl anion has 17 protons and 18 electrons for a total charge of −1. All atoms of a given element are not necessarily identical, however. The number of neutrons may vary to form different isotopes , and energy levels may differ, resulting in different nuclear isomers . For example, there are two stable isotopes of chlorine : 17 Cl with 35 − 17 = 18 neutrons and 17 Cl with 37 − 17 = 20 neutrons. The proton

13624-535: The only active development of which is through the Western Lithium Corporation in the United States. At 20 mg lithium per kg of Earth's crust, lithium is the 31st most abundant element. According to the Handbook of Lithium and Natural Calcium , "Lithium is a comparatively rare element, although it is found in many rocks and some brines, but always in very low concentrations. There are

13755-465: The ore from zoned pegmatites could be mined for a competitive price. For example, the US mines near Kings Mountain , North Carolina, closed before the beginning of the 21st century. The development of lithium-ion batteries increased the demand for lithium and became the dominant use in 2007. With the surge of lithium demand in batteries in the 2000s, new companies have expanded brine isolation efforts to meet

13886-647: The other four stable odd-odd nuclides being hydrogen-2 , boron-10 , nitrogen-14 , and tantalum-180m . Li is one of the primordial elements (or, more properly, primordial nuclides ) produced in Big Bang nucleosynthesis . A small amount of both Li and Li are produced in stars during stellar nucleosynthesis , but it is further " burned " as fast as produced. Li can also be generated in carbon stars . Additional small amounts of both Li and Li may be generated from solar wind, cosmic rays hitting heavier atoms, and from early solar system Be radioactive decay. Lithium isotopes fractionate substantially during

14017-719: The particles in the solar wind are electrons and protons, in approximately equal numbers. Because the Solar Wind Spectrometer made continuous measurements, it was possible to measure how the Earth's magnetic field affects arriving solar wind particles. For about two-thirds of each orbit, the Moon is outside of the Earth's magnetic field. At these times, a typical proton density was 10 to 20 per cubic centimeter, with most protons having velocities between 400 and 650 kilometers per second. For about five days of each month,

14148-506: The pharmaceutical industry. For laboratory organic synthesis, many organolithium reagents are commercially available in solution form. These reagents are highly reactive, and are sometimes pyrophoric . Like its inorganic compounds, almost all organic compounds of lithium formally follow the duet rule (e.g., BuLi , MeLi ). However, it is important to note that in the absence of coordinating solvents or ligands, organolithium compounds form dimeric, tetrameric, and hexameric clusters (e.g., BuLi

14279-401: The presence of a new element while analyzing petalite ore. This element formed compounds similar to those of sodium and potassium , though its carbonate and hydroxide were less soluble in water and less alkaline . Berzelius gave the alkaline material the name " lithion / lithina ", from the Greek word λιθoς (transliterated as lithos , meaning "stone"), to reflect its discovery in

14410-675: The pressure profile shape by selection of the model. The radius of the hydrated proton appears in the Born equation for calculating the hydration enthalpy of hydronium . Although protons have affinity for oppositely charged electrons, this is a relatively low-energy interaction and so free protons must lose sufficient velocity (and kinetic energy ) in order to become closely associated and bound to electrons. High energy protons, in traversing ordinary matter, lose energy by collisions with atomic nuclei , and by ionization of atoms (removing electrons) until they are slowed sufficiently to be captured by

14541-474: The production of tritium by itself, as well as a form of solid fusion fuel used inside hydrogen bombs in the form of lithium deuteride . The US became the prime producer of lithium between the late 1950s and the mid-1980s. At the end, the stockpile of lithium was roughly 42,000 tonnes of lithium hydroxide. The stockpiled lithium was depleted in lithium-6 by 75%, which was enough to affect the measured atomic weight of lithium in many standardized chemicals, and even

14672-662: The production of which is heavily affected by solar proton events such as coronal mass ejections . Research has been performed on the dose-rate effects of protons, as typically found in space travel , on human health. To be more specific, there are hopes to identify what specific chromosomes are damaged, and to define the damage, during cancer development from proton exposure. Another study looks into determining "the effects of exposure to proton irradiation on neurochemical and behavioral endpoints, including dopaminergic functioning, amphetamine -induced conditioned taste aversion learning, and spatial learning and memory as measured by

14803-445: The proton root-mean-square radius of Li is 2.18 +0.16 −0.21  fm , its neutron radius is much larger at 3.34 +0.02 −0.08  fm ; for comparison, the corresponding figures for Li are 2.076 ± 0.037 fm for the protons and 2.4 ± 0.03 fm for the neutrons. It decays by beta emission and neutron emission to Be , Be , or Be (see tables above and below). Having

14934-530: The proton drip line. The decay modes of the two isomers of Li are unknown. Lewis, G. N.; MacDonald, R. T. (1936). "The Separation of Lithium Isotopes". Journal of the American Chemical Society . 58 (12): 2519–2524. doi : 10.1021/ja01303a045 . Lithium Lithium (from Ancient Greek λίθος ( líthos )  'stone') is a chemical element ; it has symbol Li and atomic number  3. It

15065-400: The proton's mass. The rest mass of a proton is, thus, the invariant mass of the system of moving quarks and gluons that make up the particle, and, in such systems, even the energy of massless particles confined to a system is still measured as part of the rest mass of the system. Two terms are used in referring to the mass of the quarks that make up protons: current quark mass refers to

15196-479: The proton, which is due to its angular momentum (or spin ), which in turn has a magnitude of one-half the reduced Planck constant . ( ℏ / 2 {\displaystyle \hbar /2} ). The name refers to examination of protons as they occur in protium (hydrogen-1 atoms) in compounds, and does not imply that free protons exist in the compound being studied. The Apollo Lunar Surface Experiments Packages (ALSEP) determined that more than 95% of

15327-435: The pure element from its salts. It was not isolated until 1821, when William Thomas Brande obtained it by electrolysis of lithium oxide , a process that had previously been employed by the chemist Sir Humphry Davy to isolate the alkali metals potassium and sodium. Brande also described some pure salts of lithium, such as the chloride, and, estimating that lithia ( lithium oxide ) contained about 55% metal, estimated

15458-517: The quarks' exchanging gluons, and interacting with various vacuum condensates. Lattice QCD provides a way of calculating the mass of a proton directly from the theory to any accuracy, in principle. The most recent calculations claim that the mass is determined to better than 4% accuracy, even to 1% accuracy (see Figure S5 in Dürr et al. ). These claims are still controversial, because the calculations cannot yet be done with quarks as light as they are in

15589-444: The real world. This means that the predictions are found by a process of extrapolation , which can introduce systematic errors. It is hard to tell whether these errors are controlled properly, because the quantities that are compared to experiment are the masses of the hadrons , which are known in advance. These recent calculations are performed by massive supercomputers, and, as noted by Boffi and Pasquini: "a detailed description of

15720-581: The relative properties of particles and antiparticles and, therefore, is open to stringent tests. For example, the charges of a proton and antiproton must sum to exactly zero. This equality has been tested to one part in 10 . The equality of their masses has also been tested to better than one part in 10 . By holding antiprotons in a Penning trap , the equality of the charge-to-mass ratio of protons and antiprotons has been tested to one part in 6 × 10 . The magnetic moment of antiprotons has been measured with an error of 8 × 10 nuclear Bohr magnetons , and

15851-476: The rising demand. It has been argued that lithium will be one of the main objects of geopolitical competition in a world running on renewable energy and dependent on batteries, but this perspective has also been criticised for underestimating the power of economic incentives for expanded production. Lithium reacts with water easily, but with noticeably less vigor than other alkali metals. The reaction forms hydrogen gas and lithium hydroxide . When placed over

15982-443: The simplest and lightest element and was influenced by Prout's hypothesis that hydrogen was the building block of all elements. Discovery that the hydrogen nucleus is present in other nuclei as an elementary particle led Rutherford to give the hydrogen nucleus H a special name as a particle, since he suspected that hydrogen, the lightest element, contained only one of these particles. He named this new fundamental building block of

16113-473: The smallest nonzero nuclear electric quadrupole moment of any stable nucleus. Lithium-7 is by far the most abundant isotope of lithium, making up between 92.2% and 98.1% of all terrestrial lithium. A lithium-7 atom contains three protons, four neutrons, and three electrons. Because of its nuclear properties, lithium-7 is less common than helium , carbon , nitrogen , or oxygen in the Universe, even though

16244-485: The surface of the Sun) and with any type of atom. Thus, in interaction with any type of normal (non-plasma) matter, low-velocity free protons do not remain free but are attracted to electrons in any atom or molecule with which they come into contact, causing the proton and molecule to combine. Such molecules are then said to be " protonated ", and chemically they are simply compounds of hydrogen, often positively charged. Often, as

16375-415: The symbol Z ). Since each element is identified by the number of protons in its nucleus, each element has its own atomic number, which determines the number of atomic electrons and consequently the chemical characteristics of the element. The word proton is Greek for "first", and the name was given to the hydrogen nucleus by Ernest Rutherford in 1920. In previous years, Rutherford had discovered that

16506-490: The three elements synthesized in the Big Bang. Though the amount of lithium generated in Big Bang nucleosynthesis is dependent upon the number of photons per baryon , for accepted values the lithium abundance can be calculated, and there is a " cosmological lithium discrepancy " in the universe: older stars seem to have less lithium than they should, and some younger stars have much more. The lack of lithium in older stars

16637-529: Was confirmed experimentally by Henry Moseley in 1913 using X-ray spectra (More details in Atomic number under Moseley's 1913 experiment). In 1917, Rutherford performed experiments (reported in 1919 and 1925) which proved that the hydrogen nucleus is present in other nuclei, a result usually described as the discovery of protons. These experiments began after Rutherford observed that when alpha particles would strike air, Rutherford could detect scintillation on

16768-666: Was gathered mainly by the Soviets during their occupation of Afghanistan from 1979–1989". The Department of Defense estimated the lithium reserves in Afghanistan to amount to the ones in Bolivia and dubbed it as a potential "Saudi-Arabia of lithium". In Cornwall , England, the presence of brine rich in lithium was well known due to the region's historic mining industry , and private investors have conducted tests to investigate potential lithium extraction in this area. Lithium

16899-546: Was not accepted and its existence is thus unproven. No other resonances attributable to Li have been reported, and it is expected to decay by prompt proton emission (much like the diproton , He ). Lithium-4 contains three protons and one neutron. It is the shortest-lived known isotope of lithium, with a half-life of 91(9) yoctoseconds ( 9.1(9) × 10 s ) and decays by proton emission to helium-3 . Lithium-4 can be formed as an intermediate in some nuclear fusion reactions. Lithium-6

17030-436: Was said to be maximum at the centre, positive (repulsive) to a radial distance of about 0.6 fm, negative (attractive) at greater distances, and very weak beyond about 2 fm. These numbers were derived by a combination of a theoretical model and experimental Compton scattering of high-energy electrons. However, these results have been challenged as also being consistent with zero pressure and as effectively providing

17161-553: Was supported by the fact that lithium-based soaps have a higher melting point than other alkali soaps, and are less corrosive than calcium based soaps. The small demand for lithium soaps and lubricating greases was supported by several small mining operations, mostly in the US. The demand for lithium increased dramatically during the Cold War with the production of nuclear fusion weapons . Both lithium-6 and lithium-7 produce tritium when irradiated by neutrons, and are thus useful for

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