Mole. Caesium isotopes in biology

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$Stable Relative Mole isotope atomic mass fraction 133 Cs 132.$ radioactive caesium isotope.

1 Stable Relative Mole isotope atomic mass fraction 133 Cs Caesium isotopes in biology 137 Cs can be used as a tracer in fungal mycelia (mushrooms) to monitor the immobilization of this radioactive caesium isotope. After the nuclear reactor accident at Chernobyl, large quantities of 137 Cs were released as fission products into the environment. Areas with large fungal populations and an extensive matrix of underground hyphae (stems of growth from a fungus) seemed to immobilize the 137 Cs isotope, which limited the spread of the radioactive isotope [ ].

Caesium isotopes in Earth/planetary science 137 Cs is used to determine the spatial distribution of sediment type, for example, at the Watts Bar Reservoir in Tennessee (Figure 1) [405, 406]. Fig.

2 Caesium isotopes in Earth/planetary science 137 Cs is used to determine the spatial distribution of sediment type, for example, at the Watts Bar Reservoir in Tennessee (Figure 1) [405, 406]. Fig. 1: Spatial analysis of 137 Cs in sediments of Watts Bar Reservoir. (Image Source: Oak Ridge National Laboratory) [405]. Caesium isotopes in geochronology Nuclear fission of 235 U (or other fissionable materials) yields 137 Cs as a product. Although 137 Cs is not naturally present in the environment, it can be collected from nuclear reactor processing and then used as an environmental tracer. 137 Cs adheres tightly to porous sediments and will follow the movement of the sediment. By exposing sediments to 137 Cs and allowing this combination to move dynamically, gamma ray spectrometry can then be used to measure the activity of 137 Cs and monitor the movement of the radioactive sediments [ , ]. 137 Cs dating of sediments not older than 60 years is useful in natural and artificial lakes and other environments because of its widespread production and release during atmospheric nuclear weapons testing, which began in the late 1940s, plus subsequent releases, such as during the accident at the Chernobyl nuclear reactor in April The 137 Cs concentration profile in a sediment core can be matched with the historical record of 137 Cs release to determine the approximate age profile of the sediment [ , ].

3 Caesium isotopes in industry High-energy gamma rays from 137 Cs serve as food irradiation devices to remove bacteria and other harmful microorganisms (living single celled organisms such as virus, algae and fungus) from food. Although 137 Cs is not used commercially for large-scale food irradiation, it has been proposed that it can be used this way. Gamma rays from the radioactive 137 Cs destroy the DNA of organisms to enable foods to last longer (i.e. irradiation of fruits and vegetables stops the ripening process) and be contamination free [409, 410].

4 Glossary atomic number (Z) The number of protons in the nucleus of an atom. DNA deoxyribose nucleic acid, a double stranded molecule carrying genetic instructions for reproduction of organisms [return] electron elementary particle of matter with a negative electric charge and a rest mass of about kg. element (chemical element) a species of atoms; all atoms with the same number of protons in the atomic nucleus. A pure chemical substance composed of atoms with the same number of protons in the atomic nucleus [703]. fission the spontaneous (or induced by particle collision) splitting of a heavy nucleus into a pair (only rarely more) of nearly equal fission fragments (fission products) generally with some neutrons. Fission is accompanied by the release of a large quantity of energy. [return] fissionable capable of undergoing fission by interaction with particles, usually neutrons. [return] gamma rays (gamma radiation) a stream of high-energy electromagnetic radiation given off by an atomic nucleus undergoing radioactive decay. The energies of gamma rays are higher than those of X-rays; thus, gamma rays have greater penetrating power. [return] half-life (radioactive) the time interval that it takes for the total number of atoms of any radioactive isotope to decay and leave only one-half of the original number of atoms. isotope one of two or more species of atoms of a given element (having the same number of protons in the nucleus) with different atomic masses (different number of neutrons in the nucleus). The atom can either be a stable isotope or a radioactive isotope. neutron an elementary particle with no net charge and a rest mass of about kg, slightly more than that of the proton. All atoms contain neutrons in their nucleus except for protium ( 1 H). proton an elementary particle having a rest mass of about kg, slightly less than that of a neutron, and a positive electric charge equal and opposite to that of the electron. The number of protons in the nucleus of an atom is the atomic number. radioactive decay the process by which unstable (or radioactive) isotopes lose energy by emitting alpha particles (helium nuclei), beta particles (positive or negative electrons), gamma radiation, neutrons or protons to reach a final stable energy state. radioactive isotope (radioisotope) an atom for which radioactive decay has been experimentally measured (also see half-life).

5 stable isotope an atom for which no radioactive decay has ever been experimentally measured. X-rays electromagnetic radiation with a wavelength ranging from 0.01 to 10 nanometers shorter than those of UV rays and typically longer than those of gamma rays. tracer - substance used for tracking purposes. [return] References 401. M. S. Humphries, Kindness, A., Ellery, W.N., Hughes, J.C., and Benitez-Nelson, C.R. Geomorphology. 119, 88 (2010) W. G. Winn. Journal of Radioanalytical and Nuclear Chemistry. 195 (2), 345 (1995) /BF S. N. Gray, Dighton, J., Olsson, S., and Jennings, D. H. New Phytologist. 129 (3), 449 (1995) /j tb04316.x 404. J. Dighton, Clint, G.M., and Poskitt, J. Mycological Research. 95 (9), 1052 (1991) /S (09) R. H. Gardner, Hargrove, W.W., Levine, D.A., Pearson, S.M., and Rose, K.A. Spatial Analysis of Cesium in Sediments of Watts Bar Reservoir. Oak Ridge National Laboratory Feb C. R. Olsen, Larson, I.L., Lowry, P.D., Moriones, C.R., Ford, C.J., Dearstone, K.C., Turner, R.R, Kimmel B.L., and Brandt, C.C. Transport and accumulation of cesium-137 and mercury in the clinch River and Watts Bar Reservoir system. O. R. N. L. T. Publication A. V. Chesnokov, Govorun, A. P., Fedin. V. N., Ivanov, O. P., Liksonov, V. I., Potapov, V. N., Shcherbak, S. B., Smirnov, S. V., and Urutskoev, L.I. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 420 (1-2), 336 (1999) /S (98)00761-X 408. A. Albrecht, Reiser, R., Lück, A., Stoll, J.M.A. and Giger, W. Environmental Science & Technology. 32 (13), 1882 (1998) D. W. HAYER. Journal of Food Quality. 13, 147 (1990) /j tb00014.x 410. U. S. G. A. Office. GAO (2000) I. U. o. P. a. A. Chemistry. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Blackwell Scientific Publications, Oxford (1997).

Stable isotope. Relative atomic mass. Mole fraction 151 Eu Eu

$Stable isotope. Relative atomic mass. Mole fraction 151 Eu Eu$ Stable isotope Relative atomic mass Mole fraction 151 Eu 150.919 86 0.4781 153 Eu 152.921 24 0.5219 Radioactive isotope having a relatively long half-life (5 10 18 years) and a characteristic terrestrial