Transmutation Ernest

Ernest O. Lawrence, inventor of the cyclotron) This member of the 5f transition elements (actinide series) was discovered in March 1961 by A. Ghiorso, T. Sikkeland, A.E. Larsh, and R.M. Latimer. A 3-Mg californium target, consisting of a mixture of isotopes of mass number 249, 250, 251, and 252, was bombarded with either lOB or IIB. The electrically charged transmutation nuclei recoiled with an atmosphere of helium and were collected on a thin copper conveyor tape which was then moved to place collected atoms in front of a series of solid-state detectors. The isotope of element 103 produced in this way decayed by emitting an 8.6 MeV alpha particle with a half-life of 8 s. 

Ernest Rutherford, Frederick Soddy, and then Sir William Ramsay documented natural transformations of one element into another in 1902 and 1903. The artificial transmutation of one element into another, however, was first accomplished in 1919 by Rutherford, a physicist. Indeed, the field of nuclear physics has contributed the most to our understanding of the subatomic world since the 1920s. But the scientists who most advocated transmutation as a goal of research and a heuristic principle for understanding the nature of matter—the Nobel Prize winners Ramsay and Soddy, and, in a less prominent way, Sir William Crookes—were chemists, not physicists.1... 

As concerns the spontaneous transmutations undergone by the radioactive elements, the facts appear to indicate (or, at least, can be brought into some sort of order by supposing) the atom to consist of a central nucleus and an outer shell, as suggested by Sir Ernest Rutherford. The nucleus may be compared to the sun of a solar system. It is excessively small, but in it the mass of the atom is almost entirely concentrated. It is positively charged, the charge being neutralised by that of the free electrons which revolve like planets about it, and which by their orbits account for the... 

For very many years, the alchemist s dream of changing base metals into gold was ridiculed even by the most reputable of scientists. Although it was known that the nuclei of certain atoms undergo alteration in the course of natural radioactive decay, researchers inability to exercise any control over the nature or rate of these spontaneous decompositions probably did much to foster the belief that the nucleus of the atom was inviolate. However, in the year 1919 the English physicist Ernest Rutherford accomplished the first transmutation of an element, and this notable discovery was quickly followed by other equally significant developments. 

In most cases nuclear reactions result in a nuclear transmutation from one element to another. Transmutation was originally connected to the mythical "philosopher s stone" of alchemy that could turn cheaper elements into gold. When Frederick Soddy and Ernest Rutherford first recognized that radioactive decay was changing one element into another, Soddy remembered saying, "Rutherford, this is transmutation " Rutherford replied, "Soddy, don t call it transmutation. They ll have our heads off as alchemists."... 

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 ... 

In almost all of the previous examples, we have looked at nuclear reactions that occur by spontaneous decay. There are other types of nuclear reactions that can occur, known as transmutation reactions. These reactions can be induced by forcing a reaction between the nucleus of an element and nuclear particles (such as neutrons), or nuclei. Ernest Rutherford carried out the first transmutation by bombarding nitrogen-14 nuclei with alpha particles. This resulted in the production of oxygen-17 and a proton, as shown below ... 

How did Ernest Rutherford deduce that he had observed a transmutation in his cloud chamber ... 

In 1919, Ernest Rutherford performed the first laboratory conversion of one element into another element. By bombarding nitrogen-14 with high-speed alpha particles, an unstable fluorine-18 occurred, and then oxygen-17 was formed. This transmutation reaction is illustrated below. 

Rutherford, Sir Ernest (1871-1937). First to prove radioactive decay of heavy elements and to carry out a transmutation reaction (1919). Discovered half-life of radioactive elements. Nobel Prize 1908. 

Sir Ernest Rutherford achieves the first transmutation of an element, converting nitrogen into oxygen. 

Radon was discovered in 1899 by the McGill University professors Ernest Rutherford and Robert Owens, who found that radioactive thorium produced radioactive gas. They named this gaseous substance thorium emanation, later to become thoron. It was found that radium gave off a similar emanation (radon), as did actinium (actinon), in 1900 and 1904, respectively. Once the structure of the atom and the elemental transmutation process became better understood, it was determined that thoron, radon, and actinon were different isotopes of the same element (radon)— °Rn, Rn, and Rn, respectively. 

After two years of research at Oxford, Soddy served as a demonstrator (laboratory instructor) at McGill University in Montreal, Canada (1900-1902), where he worked with Ernest Rntherford, studying the gaseous emanation of radinm and showing that radioactivity involved the disintegration of radioactive atoms to form new elements. He called the process transmutation, a term that he borrowed from alchemy. 

U minerals and found the radioactive properties to be not a function of the physical or chemical forms of the uranium, but properties of the element itself. Using chemical separation methods, they isolated two new radioactive substances associated with the U minerals in 1898 and named them polonium and radium. In 1902 Ernest Rutherford and Frederick Soddy explained the nature of the process occurring in the natural decay chains as the radioactive decays of U and Th to produce new substances by transmutation. 

Ernest Rutherford, The Times reported, had recited a history of the discoveries of the last quarter of a century in atomic transmutation, including ... 

The transmutation of the elements has long been the goal of the alchemists. In 1917, Ernest Rutherford was the first person to realize that dream. Rutherford converted nitrogen-14 into oxygen-17 and a proton by bombarding a sample of with a stream of alpha particles, according to the nuclear reaction shown in Equation (2.2) ... 

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