Chemical element transmutation

Today, one century after Ernest Rutherford and Frederick Soddy postulated that in the radioactive decay one chemical element transmutes into a new one, we know of 112 chemical elements. The discoveries of elements 114 and 116 are currently waiting to be confirmed and experimentalists are embarking to discover new and heavier elements. Now where are superheavy elements located on a physicist s chart of nuclides and on the Periodic Table of the Elements - the most basic chart in chemistry ... 

It is only yesterday that we heard of a discovery by Sir William Ramsay and other scientists—working, I believe, independently— which may mean the transmutation of one chemical element into another—subject, of course, to the validity of Prof. Sir J. J. Thomson s alternative contention. We must seek to know more of the trend of recent discovery in this direction, and we need to be informed by someone who has an eye to the efforts of the past, but also a complete disregard of any a priori reasonings which actuated those efforts. 

Notice that radioactive decay actually changes one chemical element to another element, a process referred to as transmutation. 

Radioactive decay also causes chemical transmutations. The daughter nucleus in a or (3 decay is a different chemical element than the mother nucleus, but it is in the same chemical environment as the mother nucleus. Change of oxidation state or bonding is a possibility. 

Research in nuclear and radiochemistry comprises Study of radioactive matter in nature, investigation of radioactive transmutations and of nuclear reactions by chemical methods, hot atom chemistry (chemical effects of nuclear reactions) and influence of chemical bonding on nuclear properties, production of radionuclides and labelled compounds, and the chemistry of radioelements - which represent more than a quarter of all chemical elements. 

Although nuclei do not change into different elements in ordinary chemical reactions, transmutations can happen. Early chemists such as John Dalton had insisted that atoms never change into other elements, so when scientists first encountered transmutations in the I9I0s, their results were not always believed. 

Because each element has a different but fixed number of protons in the nucleus of the atom, which is the atomic number, the transmutation of one chemical element into another involves changing that number. Such a nuclear reaction requires millions of times more energy than was available through chemical reactions. Thus, the alchemist s dream of transmuting lead into gold was never chemically achievable. 

The philosophers stone of the alchemist was of course a catalyst and it was not until nearly 1800 that chemical theory - the ideas of chemical elements and the nature of chemical change - made transmutation suspect. The lingering idea of the philosophers stone may have influenced the development of the idea of catalysis. The following... 

During the eighteenth century various reports of what we would call transmutations appeared in the literature. But, in the absence of the theory of chemical elements, there was no way to distinguish between what we would now call a chemical change and a transmutation. Although most educated people came to believe that most alchemists were charlatans, there was no scientific reason why transmutation was impossible and another master of the mint. Sir Isaac Newton, took it seriously. But, in the nineteenth century, alchemy disappeared from the scientific literature. The discovery of radioactive trcinsmutations revivified "alchemy" for a short period in the earlier 1900 s and the philosophers stone made its last appeareince in the form of a Pd/asbestos catalyst. 

All matter is composed of aggregates of atoms. With the exception of radiochemistry and radioactivity (Chapter 16) atoms are neither created nor destroyed during physical or chemical changes. It has been determined that 90 chemically different atoms, the chemical elements, are naturally present on the Earth, and others have been prepared by radioactive transmutations. Chemical elements are frequently represented by symbols, which are abbreviations of the name of the element. 

According to Rutherford and Soddy, the mechanism of radioactive decay consists in transformation of chemical elements and in their natural transmutation. This was particularly clear in the case of radium, which converted into radon after emission of alpha radiation. Somewhat later, the alpha particle was found to be a doubly ionized helium atom. The decay of radium gave rise to two new elements, namely, radon and helium ... 

Transmutation processes result in the creation of new isotopes (via (n, y) reactions) or other chemical elements (via (n,o ), (n,p) or (n,P) reactions). In practice, the most important consideration in this context is the formation of atoms of inert gases, especially He (and H), which has been observed in a number of materials. The presence of these gases strongly affects defect interactions during irradiation at elevated temperatures as they readily diffuse at elevated temperatures, are barely soluble in the lattice, and are chemically inert, thus greatly affecting the development of microstructure within the material during irradiation. 

The nuclear processes of most interest to the nuclear industry are radioactive decay and the transmutation of nuclides. Whereas chemical processes relate to the interactions of orbital electrons of the atom, nuclear processes relate to interactions of neutrons, charged particles, and nuclides with the neutrons and protons in the nucleus of the atom. As noted above, there are now known about 3000 nuclides and isomers and only 287 of these are naturally occurring. More continue to be found. As Mendeleev invented the chart of the chemical elements, Emilio Segre invented the chart of the nuclides to give order to the nuclear properties and processes. 

Entities Mendeleev beheved could not exist were ones that contravened his realist attitude to chemical elements. Matter, according to Mendeleev, had three essential properties It was integral (atoms, should they exist, must be assumed to be integral and without substructme) it was immutable (transmutation between elements was impossible, an extension of the quasi-Platonic picture of chemical elements) and each element had a specified valency. Mendeleev s often-noted early resistance to inert gases stemmed from a contravention of the third principle. His opposition to electrons (first principle) and radioactivity (second principle) sustained itself until his death [Gordin, 2004, chapter 8 1998]. Similarly, ionized elements could not exist in the abstract, and thus could certainly not be present in any solutions. 

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