Isotopes of cesium

ISOTOPES Cs-133 is the only stable isotope of cesium, and it makes up all of the naturally occurring cesium found in the Earth s crust. In addition to Cs-133 there are about 36 radioactive isotopes of Cs, most of which are artificially formed in nuclear reactors. All are produced in small numbers of atoms with relatively short half-lives. The range of Cs isotopes is from Cs-113 (amu = 112.94451) to Cs-148 (amu = 147.94900). Most of these radioisotopes produce beta radiation as they rapidly decay, with the exception of Cs-135, which has a half-life of 3x10 yr, which makes it a useful research tool. Cs-137, with a half-life of 33 years, produces both beta and gamma radiation. 

Example An isotope of cesium (cesium-137) has a half-life of 30 years. If 1.0... 

The predominant isotope of cesium is 133Cs which has a nuclear spin I of 7/2 its quadrupole moment and g-factor will be denoted by Q and gi. The 19F nucleus has spin /2 of 1 /2 (and therefore no quadrupole moment) and a nuclear g-factor denoted g2. The nuclear hyperfine Hamiltonian used by English and Zorn [51] was the sum of five terms representing the 133Cs quadrupole interaction, the 133Cs nuclear spin-rotation interaction, the 19F nuclear spin-rotation interaction, the dipolar (tensorial) interaction between the 133Cs and 19F nuclear spins, and the scalar interaction between the two nuclear spins. Consistent with the conventions in use at the time, this Hamiltonian was written in the following form ... 

Only one naturally occurring isotope of cesium is known cesium-133. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element s name is the mass number. The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element. The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope. 

Fifty-two radioactive isotopes of cesium are known also. A radioactive isotope is one that breaks apart and gives off some form of radiation. 

Cesium-137 One radioactive isotope of cesium is of special importance, cesium-137. It is produced in nuclear fission reactions. Nuclear fission is the process in which large atoms break apart. Large amounts of energy and smaller atoms are produced during fission. The smaller atoms are called fission products. Cesium-137 is a very common fission product. 

This isotope of cesium can also be used to treat some kinds of cancer. One procedure is to fill a hollow steel needle with cesium-137. The... 

The only naturally occurring isotope of cesium is cesium-133, which was chosen by the International Committee of Weights and Measures in 1960 to be the worlds official timekeeper. Under this system, one second is equal to the length of time that it takes for 9,192,631,770 vibrations of radiation to be emitted by the cesium-133 atom. 

The radioactive isotopes of cesium are much more important in technical terms, especially the long-living jCs, which can be obtained relatively simply and cheaply from radioactive waste produced by uranium-based nuclear reactors. jCs is used as a y-irradiation source for technical (metallurgical) and medical applications. 

Additions of stable cesium to the environment as a result of human activities are few in number, and are also very improbable due to the low technical importance of cesium and the very low cesium content of fuels. Consequently, contamination of the atmosphere, waste waters or sewage sludges by stable cesium isotopes are largely unknown. The situation differs, however, in the case of radioactive isotopes of cesium (see Section 1.5.8), as nuclear plants - and especially those in which uranium is regained - may in exceptional circumstances cause massive pollution of the air, soil and water. 

Measured in weight the total amount of radionuclides do not represent a huge amount compared to the presence of nonradioactive components in seawater. The radioisotopes of cesium and strontium are both important in a radioecological context since they have chemical behavior resembling potassium and calcium, respectively. Cesium follows potassium in and out of the soft tissue cells whereas strontium follows calcium into bone cells and stays. Since uptake and release in organisms is due to the chemical characteristics and rarely if the element is radioactive or not, radionuclides such as Cs and °Sr have to compete with the nonradioactive isotopes of cesium and strontium. 

Cs Radioactive isotope of cesium with a30.2yearhalf-lifeproduced as a fission product of nuclear weapons explosions or in nuclear reactors. 

The other fission product nuclides, such as the isotopes of cesium, the alkaline earths and the rare earth elements, as well as tellurium and the actinides, show an... 

Rubidium was discovered ia 1861 by Bunsen and Kirchoff by means of an optical spectroscope. It was named for the prominent red lines ia its spectmm, from the Latin word rubidus meaning darkest red. Bunsen prepared free mbidium duriag the same year by an electrolytic method. After cesium, mbidium is the second most electropositive and alkaline element. The two isotopes of natural mbidium are Rb [13982-12-1] (72.15%) and Rb [13982-13-3] (27.85%). The latter is a beta-emitter having a half-life of 4.9 x 10 ° yr. Twenty-four isotopes of mbidium are known. 

When a uranium-235 atom undergoes fission, it splits into two unequal fragments and a number of neutrons and beta particles. The fission process is complicated by the fact that different uranium-235 atoms split up in many different ways. For example, while one atom of 292U is splitting to give isotopes of rubidium (Z = 37) and cesium (Z = 55), another may break up to give isotopes of bromine (Z = 35) and lanthanum (Z = 57), while still another atom yields isotopes of zinc (Z = 30) and samarium (Z = 62) ... 

The measurements that have been made at Rochester and the experience that has been gathered over the years on the operation of sputter ion sources [38] indicate that an analytical tool of unprecedented sensitivity and accuracy for isotopic ratio determinations can be constructed by coupling SIMS technology with the new accelerator technique. The only difference in principle between the experiments that have been conducted to date and the technique as it would be applied in secondary ion mass spectrometry is that the primary beam of cesium would be focussed to a fine probe of pm dimensions rather than the spot diameters of approximately 1 mm that have been used to date. 

Aston EW (1932) The isotopic constitution and atomic weights of cesium, strontium, lithium, rubidium, barium, scandium and thallium. Proc Roy Soc A 134 571 Bach RO (ed) (1985) Lithium—Current Applications in Science, Medicine, and Technology. Wiley-Interscience, New York... 

The abundances of krypton and xenon are determined exclusively from nucleosynthesis theory. They can be interpolated from the abundances of neighboring elements based on the observation that abundances of odd-mass-number nuclides vary smoothly with increasing mass numbers (Suess and Urey, 1956). The regular behavior of the s-process also provides a constraint (see Chapter 3). In a mature -process, the relative abundances of the stable nuclides are governed by the inverse of their neutron-capture cross-sections. Isotopes with large cross-sections have low abundance because they are easily destroyed, while the abundances of those with small cross-sections build up. Thus, one can estimate the abundances of krypton and xenon from the abundances of. v-only isotopes of neighboring elements (selenium, bromine, rubidium and strontium for krypton tellurium, iodine, cesium, and barium for xenon). 

Values a and b for the fission product isotopes and the partition factors ai and a2 are listed in Table V au for a given isotope, is the fraction which was retained by the local fallout glass particles, and < > is the fraction released to the cloud. Thus, from Table V, i137 is 0.153 which indicates that 15.3% of the 137Cs is retained by the local glass particles. It is interesting to note that the independent yield of cesium in the 137 mass chain is approximately 17%—the balance of the chain is formed as tellurium, iodine, and xenon. 

In 1963, a treaty was signed by the US, UK, and USSR to ban the atmospheric testing of atomic weapons. Previous testing of atomic weapons had added radioactive isotopes of strontium (Sr-90) and cesium (Cs-137) to the atmosphere. Eventually, these pollutants fell to the ground and may have entered the food chain. 

Fundamental atomic and physical properties of the alkali metals are given in Tables 1, 2, and 3. The elements are characterized by having electron configurations each with a single s orbital electron outside a noble gas core (see Table 1). Sodium and cesium are mononucUdic so that their relative atomic masses are known extremely accurately in effect, the same can be written for potassium and rubidium since their isotopes (of which there are three and two, respectively) have... 

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