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65-675: Kervran proposed that nuclear transmutation occurs in living organisms, which he called "biological transmutation". He made this claim after experimenting with chickens, which he believed showed that they were generating calcium in their eggshells while there was no calcium in their food or soil. He had no known scientific explanation for it. Such transmutations are not possible according to known physics , chemistry , and biology . Proponents of biological transmutations fall outside mainstream physics and are not part of accepted scientific discourse. Kervran's ideas about biological transmutation have no scientific basis and are considered discredited. In

130-792: A chicken's diet, they will mobilize calcium from their bones. In modern times, chicken feed is often supplemented to ensure adequate calcium intake. Science writer Joe Schwarcz has written that "the bottom line is that the Kervran effect doesn't exist... [he] simply came to the wrong conclusion based on some faulty observations." In 1993, Kervran was awarded a parodic Ig Nobel prize in Physics due to his "improbable research" in biological transmutation. The award description called him an "ardent admirer of alchemy." Organic farmers Raoul Lemaire (1884–1972) and Jean Boucher promoted Kervran's discredited theory of biological transmutation, incorporating it into

195-456: A cloud of hydrogen and helium containing heavier elements in dust grains formed previously by a large number of such stars. These grains contained the heavier elements formed by transmutation earlier in the history of the universe. All of these natural processes of transmutation in stars are continuing today, in our own galaxy and in others. Stars fuse hydrogen and helium into heavier and heavier elements (up to iron), producing energy. For example,

260-500: A heavy and light nucleus; while reactions between two light nuclei are the most common ones. Neutrons , on the other hand, have no electric charge to cause repulsion, and are able to initiate a nuclear reaction at very low energies. In fact, at extremely low particle energies (corresponding, say, to thermal equilibrium at room temperature ), the neutron's de Broglie wavelength is greatly increased, possibly greatly increasing its capture cross-section, at energies close to resonances of

325-444: A large amount of energy. The released neutrons then cause fission of other uranium atoms, until all of the available uranium is exhausted. This is called a chain reaction . Artificial nuclear transmutation has been considered as a possible mechanism for reducing the volume and hazard of radioactive waste . The term transmutation dates back to alchemy . Alchemists pursued the philosopher's stone , capable of chrysopoeia –

390-465: A minuscule amount of gold from bismuth, at a net energy loss. The Big Bang is thought to be the origin of the hydrogen (including all deuterium ) and helium in the universe. Hydrogen and helium together account for 98% of the mass of ordinary matter in the universe, while the other 2% makes up everything else. The Big Bang also produced small amounts of lithium , beryllium and perhaps boron . More lithium, beryllium and boron were produced later, in

455-489: A natural nuclear reaction, cosmic ray spallation . Stellar nucleosynthesis is responsible for all of the other elements occurring naturally in the universe as stable isotopes and primordial nuclide , from carbon to uranium . These occurred after the Big Bang, during star formation. Some lighter elements from carbon to iron were formed in stars and released into space by asymptotic giant branch (AGB) stars. These are

520-733: A nucleus) or by radioactive decay , where no outside cause is needed. Natural transmutation by stellar nucleosynthesis in the past created most of the heavier chemical elements in the known existing universe, and continues to take place to this day, creating the vast majority of the most common elements in the universe, including helium , oxygen and carbon . Most stars carry out transmutation through fusion reactions involving hydrogen and helium, while much larger stars are also capable of fusing heavier elements up to iron late in their evolution. Elements heavier than iron, such as gold or lead , are created through elemental transmutations that can naturally occur in supernovae . One goal of alchemy,

585-408: A relatively short half life to a stable isotope of ruthenium , a precious metal , there might also be some economic incentive to transmutation, if costs can be brought low enough. Of the remaining five long-lived fission products, selenium-79 , tin-126 and palladium-107 are produced only in small quantities (at least in today's thermal neutron , U -burning light water reactors ) and

650-486: A research fellow working under Rutherford, with the transmutation of nitrogen into oxygen , using alpha particles directed at nitrogen N + α → O + p. Rutherford had shown in 1919 that a proton (he called it a hydrogen atom) was emitted from alpha bombardment experiments but he had no information about the residual nucleus. Blackett's 1921–1924 experiments provided the first experimental evidence of an artificial nuclear transmutation reaction. Blackett correctly identified

715-405: A scale of decades to ~305 years ( tin-121m is insignificant because of the low yield), and are not easily transmuted because they have low neutron absorption cross sections . Instead, they should simply be stored until they decay. Given that this length of storage is necessary, the fission products with shorter half-lives can also be stored until they decay. The next longer-lived fission product

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780-399: A smaller amount of this element at the end of cycle. During the cycle, plutonium can be burnt in a power reactor, generating electricity. This process is not only interesting from a power generation standpoint, but also due to its capability of consuming the surplus weapons grade plutonium from the weapons program and plutonium resulting of reprocessing used nuclear fuel. Mixed oxide fuel

845-593: A spectrum of radioactive and nonradioactive fission products . Ceramic targets containing actinides can be bombarded with neutrons to induce transmutation reactions to remove the most difficult long-lived species. These can consist of actinide-containing solid solutions such as (Am,Zr)N , (Am,Y)N , (Zr,Cm)O 2 , (Zr,Cm,Am)O 2 , (Zr,Am,Y)O 2 or just actinide phases such as AmO 2 , NpO 2 , NpN , AmN mixed with some inert phases such as MgO , MgAl 2 O 4 , (Zr,Y)O 2 , TiN and ZrN . The role of non-radioactive inert phases

910-414: A transformation of at least one nuclide to another. If a nucleus interacts with another nucleus or particle, they then separate without changing the nature of any nuclide, the process is simply referred to as a type of nuclear scattering , rather than a nuclear reaction. In principle, a reaction can involve more than two particles colliding , but because the probability of three or more nuclei to meet at

975-414: A type of red giant that "puffs" off its outer atmosphere, containing some elements from carbon to nickel and iron. Nuclides with mass number greater than 64 are predominantly produced by neutron capture processes—the s -process and r -process –in supernova explosions and neutron star mergers . The Solar System is thought to have condensed approximately 4.6 billion years before the present, from

1040-565: Is samarium-151 , which has a half-life of 90 years, and is such a good neutron absorber that most of it is transmuted while the nuclear fuel is still being used; however, effectively transmuting the remaining Sm in nuclear waste would require separation from other isotopes of samarium . Given the smaller quantities and its low-energy radioactivity, Sm is less dangerous than Sr and Cs and can also be left to decay for ~970 years. Finally, there are seven long-lived fission products . They have much longer half-lives in

1105-456: Is mainly to provide stable mechanical behaviour to the target under neutron irradiation. There are issues with this P&T (partitioning and transmutation) strategy however: The new study led by Satoshi Chiba at Tokyo Tech (called "Method to Reduce Long-lived Fission Products by Nuclear Transmutations with Fast Spectrum Reactors" ) shows that effective transmutation of long-lived fission products can be achieved in fast spectrum reactors without

1170-441: Is one of these. Its blend of oxides of plutonium and uranium constitutes an alternative to the low enriched uranium fuel predominantly used in light water reactors. Since uranium is present in mixed oxide, although plutonium will be burnt, second generation plutonium will be produced through the radiative capture of uranium-238 and the two subsequent beta minus decays. Fuels with plutonium and thorium are also an option. In these,

1235-501: The 1960s, Kervran claimed to have conducted experiments and studies demonstrating violations of the law of conservation of mass by biological systems, according to which the amount of each chemical element is preserved in all chemical reactions. He claimed that organisms can transmute potassium into calcium by nuclear fusion in the course of making an eggshell: 19 K + 1 H → 20 Ca Since biological systems do not contain mechanisms to produce

1300-520: The Lemaire-Boucher organic farming method in the 1960s. They argued that their Lithothamnion -based fertilizer known as Calmagol underwent biological transmutation by transitioning calcium into potassium. Kervran took an interest in organic farming and was a contributor to Henri-Charles Geffroy's La Vie Claire magazine. Kervran's biological transmutation also influenced the macrobiotic diet of George Ohsawa . His book Biological Transmutations

1365-498: The Plutonium content of used MOX-fuel. The heavier elements could be transmuted in fast reactors , but probably more effectively in a subcritical reactor which is sometimes known as an energy amplifier and which was devised by Carlo Rubbia . Fusion neutron sources have also been proposed as well suited. There are several fuels that can incorporate plutonium in their initial composition at their beginning of cycle and have

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1430-572: The University of Manchester, using alpha particles directed at nitrogen N + α → O + p.  This was the first observation of an induced nuclear reaction, that is, a reaction in which particles from one decay are used to transform another atomic nucleus. Eventually, in 1932 at Cambridge University, a fully artificial nuclear reaction and nuclear transmutation was achieved by Rutherford's colleagues John Cockcroft and Ernest Walton , who used artificially accelerated protons against lithium-7, to split

1495-403: The absence of uranium in the fuel, there is no second generation plutonium produced, and the amount of plutonium burnt will be higher than in mixed oxide fuels. However, uranium-233, which is fissile, will be present in the used nuclear fuel. Weapons-grade and reactor-grade plutonium can be used in plutonium–thorium fuels, with weapons-grade plutonium being the one that shows a bigger reduction in

1560-455: The amount of plutonium-239. Some radioactive fission products can be converted into shorter-lived radioisotopes by transmutation. Transmutation of all fission products with half-life greater than one year is studied in Grenoble, with varying results. Strontium-90 and caesium-137, with half-lives of about 30 years, are the largest radiation (including heat) emitters in used nuclear fuel on

1625-454: The best-known neutron reactions are neutron scattering , neutron capture , and nuclear fission , for some light nuclei (especially odd-odd nuclei ) the most probable reaction with a thermal neutron is a transfer reaction: Some reactions are only possible with fast neutrons : Either a low-energy projectile is absorbed or a higher energy particle transfers energy to the nucleus, leaving it with too much energy to be fully bound together. On

1690-424: The course of a reaction ( exothermic reaction ) or kinetic energy may have to be supplied for the reaction to take place ( endothermic reaction ). This can be calculated by reference to a table of very accurate particle rest masses, as follows: according to the reference tables, the 3 Li nucleus has a standard atomic weight of 6.015 atomic mass units (abbreviated u ), the deuterium has 2.014 u, and

1755-632: The energy and the flux of the incident particles, and the reaction cross section . An example of a large repository of reaction rates is the REACLIB database, as maintained by the Joint Institute for Nuclear Astrophysics . In the initial collision which begins the reaction, the particles must approach closely enough so that the short-range strong force can affect them. As most common nuclear particles are positively charged, this means they must overcome considerable electrostatic repulsion before

1820-486: The energy released is 0.0238 × 931 MeV = 22.2 MeV . Expressed differently: the mass is reduced by 0.3%, corresponding to 0.3% of 90 PJ/kg is 270 TJ/kg. This is a large amount of energy for a nuclear reaction; the amount is so high because the binding energy per nucleon of the helium-4 nucleus is unusually high because the He-4 nucleus is " doubly magic ". (The He-4 nucleus is unusually stable and tightly bound for

1885-460: The equation, and in which transformations of particles must follow certain conservation laws, such as conservation of charge and baryon number (total atomic mass number ). An example of this notation follows: To balance the equation above for mass, charge and mass number, the second nucleus to the right must have atomic number 2 and mass number 4; it is therefore also helium-4. The complete equation therefore reads: or more simply: Instead of using

1950-513: The full equations in the style above, in many situations a compact notation is used to describe nuclear reactions. This style of the form A(b,c)D is equivalent to A + b producing c + D. Common light particles are often abbreviated in this shorthand, typically p for proton, n for neutron, d for deuteron , α representing an alpha particle or helium-4 , β for beta particle or electron, γ for gamma photon , etc. The reaction above would be written as Li(d,α)α. Kinetic energy may be released during

2015-444: The helium-4 nucleus has 4.0026 u. Thus: In a nuclear reaction, the total (relativistic) energy is conserved . The "missing" rest mass must therefore reappear as kinetic energy released in the reaction; its source is the nuclear binding energy . Using Einstein's mass-energy equivalence formula E  =  mc , the amount of energy released can be determined. We first need the energy equivalent of one atomic mass unit : Hence,

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2080-594: The initial formation of the Solar System (such as potassium-40 , uranium and thorium), plus the radioactive decay of products of these nuclides (radium, radon, polonium, etc.). See decay chain . Transmutation of transuranium elements (i.e. actinides minus actinium to uranium ) such as the isotopes of plutonium (about 1wt% in the light water reactors ' used nuclear fuel or the minor actinides (MAs, i.e. neptunium , americium , and curium ), about 0.1wt% each in light water reactors' used nuclear fuel) has

2145-496: The interaction between cosmic rays and matter, and nuclear reactions can be employed artificially to obtain nuclear energy, at an adjustable rate, on-demand. Nuclear chain reactions in fissionable materials produce induced nuclear fission . Various nuclear fusion reactions of light elements power the energy production of the Sun and stars. In 1919, Ernest Rutherford was able to accomplish transmutation of nitrogen into oxygen at

2210-419: The last two should be relatively inert. The other two, zirconium-93 and caesium-135 , are produced in larger quantities, but also not highly mobile in the environment. They are also mixed with larger quantities of other isotopes of the same element. Zirconium is used as cladding in fuel rods due to being virtually "transparent" to neutrons, but a small amount of Zr is produced by neutron absorption from

2275-440: The lightest chemical elements could be explained by the process of nucleosynthesis in stars. The alchemical tradition sought to turn the "base metal", lead, into gold. As a nuclear transmutation, it requires far less energy to turn gold into lead; for example, this would occur via neutron capture and beta decay if gold were left in a nuclear reactor for a sufficiently long period of time. Glenn Seaborg succeeded in producing

2340-438: The modern nuclear fission reaction discovered in 1938 by Otto Hahn , Lise Meitner and their assistant Fritz Strassmann in heavy elements. In 1941, Rubby Sherr , Kenneth Bainbridge and Herbert Lawrence Anderson reported the nuclear transmutation of mercury into gold . Later in the twentieth century the transmutation of elements within stars was elaborated, accounting for the relative abundance of heavier elements in

2405-431: The moment of realization, Soddy later recalled, he shouted out: "Rutherford, this is transmutation!" Rutherford snapped back, "For Christ's sake, Soddy, don't call it transmutation . They'll have our heads off as alchemists." Rutherford and Soddy were observing natural transmutation as a part of radioactive decay of the alpha decay type. The first artificial transmutation was accomplished in 1925 by Patrick Blackett ,

2470-614: The need for isotope separation. This can be achieved by adding a yttrium deuteride moderator. For instance, plutonium can be reprocessed into mixed oxide fuels and transmuted in standard reactors. However, this is limited by the accumulation of plutonium-240 in spent MOX fuel, which is neither particularly fertile (transmutation to fissile plutonium-241 does occur, but at lower rates than production of more plutonium-240 from neutron capture by plutonium-239 ) nor fissile with thermal neutrons. Even countries like France which practice nuclear reprocessing extensively, usually do not reuse

2535-425: The neutrons released in the fission of plutonium are captured by thorium-232 . After this radiative capture, thorium-232 becomes thorium-233, which undergoes two beta minus decays resulting in the production of the fissile isotope uranium-233 . The radiative capture cross section for thorium-232 is more than three times that of uranium-238, yielding a higher conversion to fissile fuel than that from uranium-238. Due to

2600-424: The notion of atoms (from the alchemical theory of corpuscles ) to explain various chemical processes. The disintegration of atoms is a distinct process involving much greater energies than could be achieved by alchemists. It was first consciously applied to modern physics by Frederick Soddy when he, along with Ernest Rutherford in 1901, discovered that radioactive thorium was converting itself into radium . At

2665-467: The nuclear structure of the elements. Such machines include particle accelerators and tokamak reactors. Conventional fission power reactors also cause artificial transmutation, not from the power of the machine, but by exposing elements to neutrons produced by fission from an artificially produced nuclear chain reaction . For instance, when a uranium atom is bombarded with slow neutrons, fission takes place. This releases, on average, three neutrons and

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2730-510: The nuclei involved. Thus low-energy neutrons may be even more reactive than high-energy neutrons. While the number of possible nuclear reactions is immense, there are several types that are more common, or otherwise notable. Some examples include: An intermediate energy projectile transfers energy or picks up or loses nucleons to the nucleus in a single quick (10 second) event. Energy and momentum transfer are relatively small. These are particularly useful in experimental nuclear physics, because

2795-459: The nucleus into two alpha particles. The feat was popularly known as "splitting the atom ", although it was not the modern nuclear fission reaction later (in 1938) discovered in heavy elements by the German scientists Otto Hahn , Lise Meitner , and Fritz Strassmann . Nuclear reactions may be shown in a form similar to chemical equations, for which invariant mass must balance for each side of

2860-467: The observed light curves of supernova stars such as SN 1987A show them blasting large amounts (comparable to the mass of Earth) of radioactive nickel and cobalt into space. However, little of this material reaches Earth. Most natural transmutation on the Earth today is mediated by cosmic rays (such as production of carbon-14 ) and by the radioactive decay of radioactive primordial nuclides left over from

2925-483: The one hand, it is the difference between the sums of kinetic energies on the final side and on the initial side. But on the other hand, it is also the difference between the nuclear rest masses on the initial side and on the final side (in this way, we have calculated the Q-value above). If the reaction equation is balanced, that does not mean that the reaction really occurs. The rate at which reactions occur depends on

2990-419: The potassium in the oats must combine with hydrogen to produce the calcium. He considered this a "low-energy transmutation" which became known as the "Kervran effect". There is no scientific basis for such an effect. Italian researchers who studied Kervran's theory in controlled conditions observed no transmutation. Contrary to what Kervran argued, oats are not devoid of calcium. If there isn't enough calcium in

3055-422: The potential to help solve some problems posed by the management of radioactive waste by reducing the proportion of long-lived isotopes it contains. (This does not rule out the need for a deep geological repository for high level radioactive waste .) When irradiated with fast neutrons in a nuclear reactor , these isotopes can undergo nuclear fission , destroying the original actinide isotope and producing

3120-664: The present occurs when certain radioactive elements present in nature spontaneously decay by a process that causes transmutation, such as alpha or beta decay . An example is the natural decay of potassium-40 to argon-40 , which forms most of the argon in the air. Also on Earth, natural transmutations from the different mechanisms of natural nuclear reactions occur, due to cosmic ray bombardment of elements (for example, to form carbon-14 ), and also occasionally from natural neutron bombardment (for example, see natural nuclear fission reactor ). Artificial transmutation may occur in machinery that has enough energy to cause changes in

3185-543: The product nucleus is metastable, this is indicated by placing an asterisk ("*") next to its atomic number. This energy is eventually released through nuclear decay . A small amount of energy may also emerge in the form of X-rays . Generally, the product nucleus has a different atomic number, and thus the configuration of its electron shells is wrong. As the electrons rearrange themselves and drop to lower energy levels, internal transition X-rays (X-rays with precisely defined emission lines ) may be emitted. In writing down

3250-613: The range 211,000 years to 15.7 million years. Two of them, technetium-99 and iodine-129 , are mobile enough in the environment to be potential dangers, are free ( Technetium has no known stable isotopes) or mostly free of mixture with stable isotopes of the same element, and have neutron cross sections that are small but adequate to support transmutation. Additionally, Tc can substitute for uranium-238 in supplying Doppler broadening for negative feedback for reactor stability. Most studies of proposed transmutation schemes have assumed Tc , I , and transuranium elements as

3315-475: The reaction can begin. Even if the target nucleus is part of a neutral atom , the other particle must penetrate well beyond the electron cloud and closely approach the nucleus, which is positively charged. Thus, such particles must be first accelerated to high energy, for example by: Also, since the force of repulsion is proportional to the product of the two charges, reactions between heavy nuclei are rarer, and require higher initiating energy, than those between

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3380-426: The reaction equation, in a way analogous to a chemical equation , one may, in addition, give the reaction energy on the right side: For the particular case discussed above, the reaction energy has already been calculated as Q = 22.2 MeV. Hence: The reaction energy (the "Q-value") is positive for exothermal reactions and negative for endothermal reactions, opposite to the similar expression in chemistry . On

3445-594: The reaction mechanisms are often simple enough to calculate with sufficient accuracy to probe the structure of the target nucleus. Only energy and momentum are transferred. Energy and charge are transferred between projectile and target. Some examples of this kind of reactions are: Usually at moderately low energy, one or more nucleons are transferred between the projectile and target. These are useful in studying outer shell structure of nuclei. Transfer reactions can occur: Examples: Reactions with neutrons are important in nuclear reactors and nuclear weapons . While

3510-420: The regular zircalloy without much ill effect. Whether Zr could be reused for new cladding material has not been subject of much study thus far. Nuclear reaction In nuclear physics and nuclear chemistry , a nuclear reaction is a process in which two nuclei , or a nucleus and an external subatomic particle , collide to produce one or more new nuclides . Thus, a nuclear reaction must cause

3575-417: The same reason that the helium atom is inert: each pair of protons and neutrons in He-4 occupies a filled 1s nuclear orbital in the same way that the pair of electrons in the helium atom occupy a filled 1s electron orbital ). Consequently, alpha particles appear frequently on the right-hand side of nuclear reactions. The energy released in a nuclear reaction can appear mainly in one of three ways: When

3640-403: The same time at the same place is much less than for two nuclei, such an event is exceptionally rare (see triple alpha process for an example very close to a three-body nuclear reaction). The term "nuclear reaction" may refer either to a change in a nuclide induced by collision with another particle or to a spontaneous change of a nuclide without collision. Natural nuclear reactions occur in

3705-409: The speed, temperature, and pressure necessary for such reactions, even for extremely short periods, this contradicts basic physical laws. Kervran said that prior studies and reports of industrial carbon monoxide accidents supported his work. Kervran said that enzymes can facilitate biological transmutations using the weak nuclear force , by what he called "neutral currents." His response to criticism

3770-412: The targets for transmutation, with other fission products, activation products , and possibly reprocessed uranium remaining as waste. Technetium-99 is also produced as a waste product in nuclear medicine from Technetium-99m , a nuclear isomer that decays to its ground state which has no further use. Due to the decay product of Tc (the result of Tc capturing a neutron) decaying with

3835-481: The transformation of base metals into gold. While alchemists often understood chrysopoeia as a metaphor for a mystical or religious process, some practitioners adopted a literal interpretation and tried to make gold through physical experimentation. The impossibility of the metallic transmutation had been debated amongst alchemists, philosophers and scientists since the Middle Ages. Pseudo-alchemical transmutation

3900-440: The transmutation of base substances into gold, is now known to be impossible by chemical means but possible by physical means. As stars begin to fuse heavier elements, substantially less energy is released from each fusion reaction. This continues until it reaches iron which is produced by an endothermic reaction consuming energy. No heavier element can be produced in such conditions. One type of natural transmutation observable in

3965-406: The underlying integration process and the identity of the residual nucleus. In 1932, a fully artificial nuclear reaction and nuclear transmutation was achieved by Rutherford's colleagues John Cockcroft and Ernest Walton , who used artificially accelerated protons against lithium-7 to split the nucleus into two alpha particles. The feat was popularly known as "splitting the atom", although it was not

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4030-512: The universe. Save for the first five elements, which were produced in the Big Bang and other cosmic ray processes, stellar nucleosynthesis accounted for the abundance of all elements heavier than boron . In their 1957 paper Synthesis of the Elements in Stars , William Alfred Fowler , Margaret Burbidge , Geoffrey Burbidge , and Fred Hoyle explained how the abundances of essentially all but

4095-490: Was first translated by Michel Abehsera, an Ohsawa disciple, in 1972. In French: English translations: Nuclear transmutation Nuclear transmutation is the conversion of one chemical element or an isotope into another chemical element. Nuclear transmutation occurs in any process where the number of protons or neutrons in the nucleus of an atom is changed. A transmutation can be achieved either by nuclear reactions (in which an outside particle reacts with

4160-471: Was outlawed and publicly mocked beginning in the fourteenth century. Alchemists like Michael Maier and Heinrich Khunrath wrote tracts exposing fraudulent claims of gold making. By the 1720s, there were no longer any respectable figures pursuing the physical transmutation of substances into gold. Antoine Lavoisier , in the 18th century, replaced the alchemical theory of elements with the modern theory of chemical elements, and John Dalton further developed

4225-405: Was to claim that physical laws do not apply to biological reactions, which contradicts the mainstream understanding that physical laws apply for all scales and conditions. Kervran suggested that under the right conditions, potassium could combine with hydrogen to form calcium. He questioned how chickens fed a diet of oats could produce eggshells composed of calcium carbonate and concluded that

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