Radiations from Radioactive Substances

It may also happen, we may add (e.g. in every j8-disintegration), that two chemically different elements have the same atomic weight these are called isobars. 

By magnetic s( paration of ca,nal rays of litliiiim, it lia,s ovcvn been found possible (Olipliaut, Shire aaid Orowtlier, 1934) to obtain visibly separated deposits of the two lithiuin isotopes (G and 7), which can bo employed for other ( .xperiments. 

Ilecently (1933) G. Hertz lias succeeded in separating isotopes by a 

These divergencies, which in spite of their sliglitness an - of the highest importance, will be discussed later ( 4, p. 55). 

Here we may once again summarize the ideas wiiicli. for somcdihing like two decades dominated physics. 

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The compound is oxidized by moist air forming basic iron(III) sulfate. Aqueous solutions exposed to air also undergo oxidation the reaction, however, is very slow. The rate of oxidation increases with temperature and the pH. In alkaline medium, the oxidation is much faster. In solution, it also is oxidized to Fe + by radiations from radioactive substances. This reaction is utilized to measure the radiation dose in dosimeter solutions. 

Professor of physics at MoGill, Manchester, and Cambridge Universities. He identified the three types of radiations from radioactive substances, and devised methods for counting alpha particles and for determining the number of free positive electrons in the nucleus of an atom. 

Rutherford, Radiation from Radioactive Substances (Cambridge Cambridge University Press, 1930). The woeful tale of cold fusion, and the precedent in the work of Pareth and Peters, Is recounted In F. Close, Too Hot To Handle (Princeton Princeton University Press, 1991). 

Radium Barium Platinocyanide.—-Since the majority of platino-cyanides fluoresce under the influence of radiations from radioactive substances, the radium salt should be self-luminous. The radium barium salt was prepared1 by dissolving radioactive barium chloride in water and boiling the solution with excess of silver platinocyanide. After filtering off insoluble silver salts the solution was allowed to crystallise in a desiccator. 

J. Chadwick, C. D. Ellis, Radiation from Radioactive Substances, Cambridge University Press, 1930). 

E. Rutherford, J. Chadwick, C. D. Ellis, Radiation from Radioactive Substances, Cambridge University Press, Cambridge, 1930 R. D. Evans, The Atomic Nucleus, McGraw-Hill, New York, 1955... 

We may also refer here to various methods for the determination of L, which make use of the radiations from radioactive substances. We may,... 

Because of the penetrating nature of gamma radiation, overexposure of the body to it results in deep-seated organic damage. Of the three types of radiation from radioactive substances, gamma radiation is by far the most serious external hazard and is the one that requires heavy shielding and remotely controlled operations. 

Lord Rutherford, J. Chadwick and C. Ellis Radiation from radioactive substances. Cambridge University Press 1930. 

Roberts JC, Newmyer SL, Mercer-Smith JA, Schreyer SA, Lavallee DK (1989) Int J Radiat Appl Instrum Part A, Appl Radiat Isot 40 775 Rubinson W (1949) J Chem Phys 17 542 Rutherford E, Chadwick J, Ellis CD (1930) Radiations from radioactive substances. Cambridge University Press, Cambridge... 

The use of radioactive isotopes has had a profound effect on the practice of medicine. Radioisotopes were first used in medicine in the treatment of cancer. This treatment is based on the fact that rapidly dividing cells, such as those in cancer, are more adversely affected by radiation from radioactive substances than are cells that divide more slowly. Radium-226 and its decay product radon-222 were nsed for cancer therapy a few years after the discovery of radioactivity. Today gamma radiation from cobalt-60 is more commonly used. 

Exposure of people to radiation or radioactive substances, which can either be external exposure from sources outside the body or internal exposure from sources inside the body. The exposure can be classified as either normal or potential exposure either occupational, medical or public exposure and, in intervention situations, either emergency or chronic exposure. 

Emanations from radioactive substances affect photographic plates just as ordinary visible light does. Becquerel s discovery of radioactivity resulted from the unexpected exposure of such a plate, wrapped in black paper, by a nearby enclosed sample of a uranium-containing compound, potassium uranyl sulfate. After a photographic plate has been developed and fixed, the intensity of the exposed spot is related to the amount of radiation that struck the plate. Quantitative detection of radiation by this method is difficult and tedious. 

The danger from radioactive substances is mainly due to the detrimental effects of the emitted ionizing radiation however, there are also toxic effects at the level of biochemical reactions. The most iihportant effects of radioactive radiation from accumulated radionuclides are manifested at a much later date in the form of genetic consequences. There are also local effects, since the radionucfides are frequently accumulated in a certain critical organ ( °Sr in bones, Cs in muscles, etc.). Thus, the local radiation dose can exceed by a factor as high as 50 the mean whole-body dose. In many cases, tumour growth may be induced. 

A variety of methods have been devised to detect emissions from radioactive substances. Becquerel discovered radioactivity because of the effect of radiation on photographic plates. Photographic plates and film have long been used to detect radioactivity. The radiation affects photographic film in much the same way as X rays do. With care, film can be used to give a quantitative measure of... 

In medicine, radioactive nuclides, such as the artificial radioactive nuclide cobalt-60, are used to destroy certain types of cancer cells. Many radioactive nuciides are aiso used as radioactive tracers, which are radioactive atoms that are inccrpcrated into substances so that movement of the substances can be foiiowed by radiation detectors. Detection of radiation from radioactive tracers can be used to diagnose cancer and other diseases. 

Radioactivity is a natural phenomenon and natural sources of radiation are features of the environment. Radiation and radioactive substances have many beneficial applications, ranging from power generation to uses in medicine, industry and agriculture. The radiation risks to workers and the public and to the environment that may arise from these applications have to be assessed and, if necessary, controlled. 

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