Sodium nuclides

A nuclide is an atom characterized by a definite atomic number and mass number. The shorthand notation for any nuclide consists of the symbol of the element with the atomic number written as a subscript on the left and the mass number as a supCT-script on the left. You write the nuclide symbol for the naturally occurring sodium nuclide as follows ... 

What nuclide is produced by (a) a decay of polonium-21 1 (b) (3 decay of sodium-24 ... 

Self-Test 17.2A Identify the nuclide produced and write the nuclear equation for (a) electron capture by beryllium-7 (b) positron emission by sodium-22. 

Figure 1. Elemental distribution of fission waste nuclides on a sodium titanate column. The distribution shown on the left was determined from qualitative analyses of the numbered column segments. The Cs and Na distributions on the right were obtained by quantitative analyses of each numbered segment. (O), Cs ( ), Na.

The waste nuclides were fractionated on the column into several hands as shown in Fig. 1 for a sodium titanate column. 

Therefore, the preliminary investigation described herein examined several aspects of the behavior of the equilibrium distribution coefficients for the sorption of rubidium, cesium, strontium, barium, silver, cadmium, cerium, promethium, europium, and gadolinium from aqueous sodium chloride solutions. These solutions initially contained one and only one of the nuclides of interest. For the nuclides selected, values of Kp were then... 

An important reaction used quite widely for this purpose is irradiation by neutrons and measurement of die energies of radiations emitted. The source of the neutrons may be a nuclear reactor, a particle accelerator, or an isotopic source, that is, a sealed container in which neutrons are produced by alpha rays emitted by a source such as radium, sodium-24(24Na), yttrium-88f8sY), etc., and arranged so that the alpha rays react-with a substance such as beryllium which in turn emits neutrons. The neutrons react with stable nuclides in the sample to produce radioactive ones. Thus... 

Radiation beams induce radioactivity primarily by photonuclear reactions. In these reactions, the absorption of energy from the incident electron, x-ray, or 7-ray will produce an excited nucleus that will then emit a neutron, proton, triton, 7-ray, or other secondary radiation. The chart of the nuclides from carbon to sodium in Figure 1 demonstrates the type of nuclide resulting from the emission of a secondary radiation from a given parent nuclide (10). The threshold energies necessary for the incoming radiation to produce a secondary radiation are given for a few of the reactions most relevant to this report. 

Figure 1. Chart of nuclides from carbon to sodium, illustrating vai ious processes for production of radionuclides (10)...

Dozol proposed the removal of these nuclides from acidic waste containing large amounts of sodium by implementing an SLM containing both tBuB21C7 and DC18C6. The removal of cesium was incomplete due particularly to an insufficient selectivity cesium over sodium of tBuB21C7.121-124... 

M,A) compare with atomic number and atomic weight. The total number of protons and neutrons in an atom or ion. In nuclide symbols the mass number is given as a leading superscript. In isotope names (e. g. carbon-14, sodium-23) the mass number is the number following the element name. 

Positron production occurs for nuclides below the zone of stability (those nuclides whose neutron/proton ratios are too small). The positron is a particle with the same mass as the electron but opposite charge. An example of a nuclide that decays by positron production is sodium-22 ... 

Neutron Activation Analysis. Magnesium-26 has a small cross section of 0.03 b. The product of irradiation with thermal neutrons is Mg (1 9.5m). As shown in Table 1, several elements commonly present in biological materials give rise to radioactive nuclides with radiations at energy levels close to those characteristic of Mg. Neutron activation was used in the first trials of Mg as an in vivo tracer when measurements were made with a well-type Nal-Tl crystal detector (14,21). Under these conditions the presence of sodium, altuninum and manganese in the samples interfered in the accurate detection of Mg, but could be reduced or eliminated by sample purification. 

This reaction liberated 17.3 MeV, the mass afterwards being 0.0186 AMU less than before. Beryllium, fluorine, sodium and magnesium provide nuclides which undergo proton-induced reactions. Nitrogen-14 yields carbon-11, a positron-emitter with a half-life of twenty minutes. 

A 0.1 ml aliquot of the dissolved spent fuel solution was diluted by adding 50 mL of pure water. The sample solution was heated and dried, and was dissolved again in 3 mL of 0.5 moEdm hydrochloric acid. The resulted hydrochloric dissolver solution was loaded onto resin (8 mL column volume). Tertiary pyridine resin of a non-support type was used as pre-filter anion exchange resin. After sample loading, the column was fed with 4 column volumes of 0.5 mol/dm hydrochloric acid solution. The resin was rinsed by pure water of 4 column volumes. Then. 1 mL of resin was taken from the column and rinsed again by pure water. After the rinse, the rinsing water and resin were encapsulated in a plastic vial. Furthermore, 3 column volumes of 1 mol/dm sodium hydroxide solution were fed to the resin. After the alkali rinse, the resin and eluted sodium hydroxide solution were analyzed by y-ray spectrometry to confirm the adsorbed nuclides. 

The investigation of isotopic separations in systems with cyclic polyethers has been carried out up to now for the elements lithium, calcium and sodium, in particular. Among these elements, the enrichment of Li is of essential importance for the production of tritium and that of the heavy calcium isotopes for medical labeling experiments. An enrichment aspect does not exist for the monoisotopic element sodium. Investigations with the radioactive nuclides Na and Na are obviously of interest for fundamental investigations because these isotopes can be easily and precisely measured by their y-activity. Except for uranium, most of the investigations on other chemical exchange systems with metal ions are also based on measurements with lithium and calcium, respectively. 

The complex formation between Sc and SeOj" was studied by measurement of the distribution of Sc between the aqueous phase and a cation exchanger at selenate concentrations in the range 0 to 0.167 M. Sodium perchlorate was added to keep the ionic strength at / = 0.5 M. The radioactive nuclide Sc was used to follow the distribution ratio at a total scandium concentration of 2 x 10 M. Measurements were carried out at 298.15, 308.15, and 318.15 K and the pH was adjusted to 4.0 to 4.5. No disturbance from the hydrolysis of Sc occurs at this pH according to the paper although this would be expected from the data in [76BAE/MES]. 

In series 2 a silver nitrate solution spiked with the radioactive nuclide "°Ag was mixed with a sodium selenite solution. The pH was again adjusted from about 1.2 to 12.5 in the mixtures. After equilibration the phases were separated and the pH determined. The total concentration of dissolved silver was found by scintillation spectrometry. The solubility determinations were performed at total concentrations of selenite at 6.45 X 10 0.10, and 0.20 M. 

In nuclear notation, the element symbol refers to the nucleus only, so a proton is also sometimes represented as jH.) The number of neutrons N) in a nucleus is the mass number (/ ) minus the atomic number (Z) N = A — Z. The two naturally occurring isotopes of chlorine, for example, have 17 protons (Z = 17), but one has 18 neutrons (nCl, also written Cl) and the other has 20 ( Cl, or Cl). Nuclides can also be designated with the element name followed by the mass number, for example, chlorine-35 and chlorine-37. Despite some small variations, in naturally occurring samples of an element or its compounds, the isotopes of the element are present in particular, fixed proportions. Thus, in a sample of sodium chloride (or any Cl-containing substance), 75.77% of the Cl atoms are chlorine-35 and the remaining 24.23% are chlorine-37. 

Low background /F counting was also used to determine Tc in seawater. The nuclide was preconcentrated from seawater by adsorbing " TcOj on an anion exchanger. It was purified from other radionuclides by scavenging with iron(lll)-oxide hydrate and extracting from sodium hydroxide solution into methyl ethyl ketone. 

Potassium provides a natural radioactive background of waters because natural potassium contains 0.0118 % of the radioactive nuclide. The contents of sodium and potassium in waters for various industries is usually not significant. The exception is the requirement for water quality to be used for high pressure steam boilers, as under higher pressures insoluble sediments (incrustations) of the type Na.2 0.R2 03.xSi02.j/H20 can be formed. 

Which mode or production is utilized dep ds on several factors. The length of time for production, separation and purification processes, the time from production to shipping, and the shipping time determine the half-life with which it is practical to work. The type of experiment and equipment available for handling and measurement determines the preferable decay type and intensity. All these factors must be considered in determining which nuclide is to be used. For example, if in an experiment requiring sodium tracer these aspects indicate the necessity of a time of at least several weeks, the use of... 

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