Copper isotope abundances

Properties of T2O. Some important physical properties of T2O are Hsted in Table 2. Tritium oxide [14940-65-9] can be prepared by catalytic oxidation of T2 or by reduction of copper oxide using tritium gas. T2O, even of low (2—19% T) isotopic abundance, undergoes radiation decomposition to form HT and O2. Decomposition continues, even at 77 K, when the water is fro2en. Pure tritiated water irradiates itself at the rate of 10 MGy/d (10 rad/d). A stationary concentration of tritium peroxide, T2O2, is always present (9). AH of these factors must be taken into account in evaluating the physical constants of a particular sample of T2O. 

Mulliken also studied other band spectra of diatomic molecules. Only one such study will be mentioned here and that is his study of copper iodide (Mulliken 1925c), where he examined the copper isotope effect. Mulliken s pioneering work was followed by more papers on isotope effects on electronic spectra (visible and UV) which will not be detailed here. Many of these papers deal with diatomics since the theory of such spectra is much better understood than that for general polyatomic systems. Further discussion of isotope effects on spectra will be mainly restricted to their use in the discovery of less abundant isotopes. 

Shields WR, Murphy TJ, Gamer EL (1964) Absolute isotopic abundance ratio and the atomic weight of a reference sample of copper. J Res NBS 68A 589-592... 

Walker EC, Cuttitta F, Senftle FE (1958) Some natural variations in the relative abundance of copper isotopes. Geochim Cosmochim Acta 15 183-194... 

Measurement of the isotope abundances of a chemical element is based on the fact that the sum of all abundances of isotopes with the same Z is 100 %. For example, copper possesses two stable isotopes with m/z = 63 and 65. If the isotope ratio 63Cu/65Cu has been determined, e.g., by mass spectrometry, then the isotope abundance of 65Cu ( ) can be obtained by ... 

These ions were identified by mass measurement as well as their isotopic abundances. Resolution for these spectra was approximately 5,000 which was adequate to separate CuS2 from traces of I present on the surface as a contaminant in both samples. The analysis was confirmed by Auger spectroscopy, which clearly showed the presence of sulfur on the surface. The contamination was later found to have resulted from vulcanized rubber that had come in contact with the stained copper parts. 

Copper is a corrosion-resistant metal that is used extensively in plumbing and wiring. Copper exists as two naturally occurring isotopes SjgCu (62.93 u) and SjgCu (64.93 u). These isotopes have isotopic abundances of 69.1% and 30.9% respectively. Calculate the average atomic mass of copper. 

Thermal ionization has been used to determine isotopic abundance of virtually all the elements We have recently extnded our own capability in this direction by adapting the silica gel/phosphoric acid filament coating technique (5) to our system Five 1 of a fine silica gel suspension is placed on a filament Five l of the analyte ion solution is coated, dried then coated with 2 pi of a 0 7N phosphoric acid solution and heated until dry again The analysis is performed in a similar manner as before, except that the signal is more transient and somewhat less intense than the calcium analysis With this approach, however, we have made natural abundance isotope ratio measurements on zinc, copper, and magnesium Table II shows our measurements compared to the accepted values, shown in parenthesis, for these elements The isotope used as reference... 

The molecular constants were corrected for normal isotopic abundance of both copper and chlorine and were calculated from the... 

No general statement can be made about the elements that can be determined and the samples that can be analyzed, because these depend on the nuclear characteristics of the target nuclide (isotopic abundance), the nuclear reaction (cross-section and related parameters such as threshold energy and Coulomb barrier), and the radionuclide induced (half-life, radiation emitted, energy, and its intensity) for the analyte element, the possible interfering elements and the major components of the sample. CPAA can solve a number of important analytical problems in material science (e.g., determination of boron, carbon, nitrogen, and oxygen impurities in very pure materials such as copper or silicon) and environmental science (e.g., determination of the toxic elements cadmium, thallium, and lead in solid environmental samples). As these problems cannot be solved by NAA, CPAA and NAA are complementary to each other. 

Copper has two naturally occurring isotopes. Cu-63 has a mass of 62.939 amu and relative abundance of 69.17%. Use the atomic weight of copper to determine the mass of the other copper isotope. 

First of all, the data in the table are fudged for the actual irradiation space named (epithermal and fast neutron activation is included). Second, normal isotopic abundances are already factored into the tables. Let s calculate activity produced by irradiation of 2.5 grams of copper for 30 minutes. The table shows two copper activation products, Cu " and Cu . Cu " has a 4.61E4 sec (12.82 hour)... 

To make this a little easier to understand, let us take a closer look at an element such as copper, which only has two different isotopes—one with an atomic mass of 63 ( Cu) and another with an atomic mass of 65 ( Cu). They both have the same number of protons and electrons, but differ in the number of neutrons in the nucleus. The natural abundances of Cu and Cu are 69.1% and 30.9%, respectively, which gives copper a nominal atomic mass of 63.55—the value you see for copper in atomic weight reference tables. Details of the atomic structure of the two copper isotopes are shown in Table 2.1. 

PRACTICE EXAMPLE A Calculate the number of Cu atoms in a cubic crystal of copper that measures exactly 25 nm on edge. The density of copper is 8.92 g/cm and the percent isotopic abundance of Cu is 69.17%. 

Monel metal is a corrosion-resistant copper-nickel alloy used in the electronics industry. A particular alloy with a density of 8.80 g/cm and containing 0.022% Si by mass is used to make a rectangular plate 15.0 cm long, 12.5 cm wide, 3.00 mm thick, and has a 2.50 cm diameter hole drilled through its center. How many silicon-30 atoms are found in this plate The mass of a silicon-30 atom is 29.97376 u, and the percent isotopic abundance of silicon-30 is 3.10%. 

Derived from the German word meaning devil s copper, nickel is found predominantly in two isotopic forms, Ni (68% natural abundance) and Ni (26%). Ni exists in four oxidation states, 0, I, II, III, and IV. Ni(II), which is the most common oxidation state, has an ionic radius of —65 pm in the four-coordinate state and —80 pm in the octahedral low-spin state. The Ni(II) aqua cation exhibits a pAa of 9.9. It forms tight complexes with histidine (log Af = 15.9) and, among the first-row transition metals, is second only to Cu(II) in its ability to complex with acidic amino acids (log K( = 6-7 (7). Although Ni(II) is most common, the paramagnetic Ni(I) and Ni(III) states are also attainable. Ni(I), a (P metal, can exist only in the S = state, whereas Ni(lll), a cT ion, can be either S = or S =. ... 

Making and Using Tables Data Table 3 shows the isotopic mass and relative abundance for the most common isotopes of copper and zinc. 

Mar hal CN, Douchet C, Nicolas E, Albarede F (2000) The abundance of zinc isotopes as a marine biogeochemical tracer. Geochem Geophys Geosyst 1 1999GC-000029 Marechal C, Albarede F (2002) Ion-exchange fractionation of copper and zinc isotopes. Geochim Cosmochim Acta 66 1499-1509... 

Ripley EM, Brophy JG, Li C (2002) Copper solubility in a basaltic melt and sulfide liq-uid/silicate melt partition coefficients of Cu and Fe. Geochim Cosmochim Acta 66 2791-2800 Rosman KJR (1972) A survey of the isotopic and elemental abundances of zinc. Geochim Cosmochim Acta 36 801-819. 

Isotopes can be divided into two fundamental kinds, stable and unstable (radioactive) species. The number of stable isotopes is about 300 whilst over 1,200 unstable ones have been discovered so far. The term stable is relative, depending on the detection limits of radioactive decay times, hi the range of atomic numbers from 1 (H) to 83 (Bi), stable nuclides of all masses except 5 and 8 are known. Only 21 elements are pure elements, in the sense that they have only one stable isotope. AU other elements are mixtures of at least two isotopes. The relative abundance of different isotopes of an element may vary substantially. In copper, for example, Cu accounts for 69% and Cu for 31% of all copper nuclei. For the light elements, however, one isotope is predominant, the others being present only in trace amounts. 

Chlorine is the major anion in surface- and mantle-derived fluids. It is the most abundant anion in hydrothermal solutions and is the dominant metal complexing agent in ore forming environments (Banks et al. 2000). Despite its variable occurrence, chlorine isotope variations in natural waters conunonly are small and close to the chlorine isotope composition of the ocean. This is also true for chlorine from fluid inclusions in hydrothermal minerals which indicate no significant differences between different types of ore deposits such as Mississippi-Valley and Porphyry Copper type deposits (Eastoe et al. 1989 Eastoe and Guilbert 1992). 

Protons have a spin 1 = and therefore often give rise to doublets. Nitrogen-14 has 1 = 1 while N has 1 = use of N can therefore simplify EPR spectra when hyperfine coupling to nitrogen is important. Both of the naturally abundant isotopes of copper have 1 =, and their magnetic moments are similar. Numerous other elements can give rise to hyperfine splitting either in naturally abundant isotopic forms or in less common isotopes after enrichment. 

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