Nuclear transmutations, artificial first

TRANSMUTATION. The natural or artificial transformation of atoms of one element into atoms of a different element as the result of a nuclear reaction. The reaction may be one in which two nuclei interact, as in the formation of oxygen from nitrogen and helium nuclei (/3-particles), or one in which a nucleus reacts widi an elementary particle such as a neutron or proton. Thus, a sodium atom and a proton form a magnesium atom. Radioactive decay, e.g., of uranium, can be regarded as a type of transmutation. The first transmutation was performed bv the English physicist Rutherford in 1919. 

Lord Rutherford and his group of scientists were the first persons to produce and detect artificial nuclear transmutations in 1919. He bombarded nitrogen in the air with the a-particles emitted in the decay of Po. The transmutation reaction involved the absorption of an a-particle by the nuclei to produce and a proton (a hydrogen nucleus). This reaction can be written as... 

Natural Radioactivity and Nuclear Transmutation Unstable nuclei undergo spontaneous decay with the emission of radiation and particles. All nuclear decays obey first-order kinetics. The half-lives of several radioactive nuclei have been used to date objects. Stable nuclei can also be made radioactive by bombardment with elementary particles or atomic nuclei. Many new elements have been created artificially in particle accelerators where such bombardments occur. 

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... 

Note that in equation (10), as in the other nuclear equations listed, atomic numbers and mass numbers are both conserved. This reaction was the first artificial transmutation, carried out (as contrasted to spontaneous transmutations or natural radioactivity in which one nucleus is transformed to another, irrespective of the influence of man). The a particle in equation (10) is the projectile and the nitrogen nucleus the target. 

The first indication of the modern concept of an element is to be found as early as Boyle (1627-1691), who was, however, far in advance of his time. Lavoisier (1743-1794) gives the purely empirical definition of an element, still valid in chemistry, as a substance which cannot be divided by any means or by any conversion. We must make an exception at present only for nuclear processes in which, both in natural radioactivity and in artificial processes brought about by neutrons, protons, etc., transmutation of the elements can take place. 

The first artificially induced nuclear reaction causes the transmutation of nitrogen into an isotope of oxygen by bombarding nitrogen gas with alpha particles. 

Give equations for (a) the first transmutation of an element obtained in the laboratory by nuclear bombardment, and for (b) the reaction that produced the first artificial radioactive isotope. 

Artificial transmutations. Everyone is more or less fomiliar with the dreams, shattered by Dalton, of the alchemists who attempted to transform a cheap metal into gold. With the postulation of the nuclear theory of the atom, artificial transmutation came to appear feasible. The first induced transmutation was demonstrated in 1919 by Rutherford, who exposed nitrogen to a particles from radium and detected the production of protons ... 

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