Isotope gallium

A series of papers by Merz and Riedel describe work designed to compare radiochemical behaviour following n,y n,p E.C. and p decay. Gallium isotopes are produced in most of the cases studied, but isotopes of Sn, Pb, Ge and Sb were also involved. Unfortunately, the various chromatography fractions were not well identified, so that it is not easy to draw definite conclusions from this work. Nevertheless, several things do appear to be clear. Some interesting data are presented in Table 5, comparing the effects of electron capture, neutron capture, and the (n,p) reaction. 

Bombardment of natural copper (isotopes 63 and 65 with protons yields isotope A, together with a fourth zinc isotope, D, a K eapturer. Bombardment of natural gallium, (isotopes 69 and 71) with energetic deutcrons yields B, but not A, C, or D. 

The elimination of gallium from rats is rapid, with excretion occurring primarily via the urinary route during the first 24 h after treatment. Fecal elimination appears not to result from biliary excretion, but seems to occur via passage of gallium across the gastric wall from the blood into the stomach (Maurel et al. 1974). After intravenous injection in humans, 25-60% of the dose is excreted in the urine within the first 24 h, but subsequent excretion occurs more slowly via the bowel (Krakoff et al. 1979, Hoffer 1980). In a human subject injected with a gallium isotope, 10% of the dose was excreted within 13 days (Priest et al. 

Gagarinite structure, 846 Galactose oxidase, 700 copper, 655 Galena brines, 853 depression, 783 dissolution, 787 humic acids, 861 Gallium isotopes... 

Fig.9.34. Superimposed hyperfine quantum beats for the two stable gallium isotopes and the corresponding Fourier transform displaying the beat frequencies [9.130]...

Gallium has two naturally occurring isotopes 69Ga, with atomic mass 68.9257 amu, and 71Ga, with atomic mass 70.9249 amu. The percent abundance of 69Ga can be estimated to be which of the following ... 

Note that only in the case of gallium, with a deep subcooling, the reference is linked to the melting point instead that to the freezing point. a All substances (except 3 He) are of natural isotopic composition. e-H2 is hydrogen at the equilibrium concenttation of the ortho and para molecular forms. 

D. D. Clayton, Handbook of Isotopes in the Cosmos Hydrogen to Gallium, Cambridge University Press, 2003. 

Gallium is non-essential, but on account of the similarity between Ga3+ and Fe3+ it binds to iron transport and storage proteins such as transferrin and ferritin. The radioactive isotope of gallium, 67Ga, concentrates to a large extent in many tumours and at sites of inflammation and infection, and since many tumours overexpress the transferrin receptor it can be used for tumour imaging. 

ISOTOPES There are 33 isotopes of gallium, two of which are stable. They are Ga-69, which makes up 60.108% of the elemenfs presence in the Earth s crust, and Ga-71, which contributes 39.892% of the gallium found in the Earth s crust. All the other 31 isotopes are radioactive with half-lives ranging from a few nanoseconds to about 15 hours. 

The ratio of the number of atoms of the isotopes MGa and 71Ga in eight samples from different sources was measured in an effort to understand differences in reported values of the atomic mass of gallium 11... 

J. W. Gramlich and L. A. Mach Ian, Isotopic Variations in Commercial High-Purity Gallium, Anal. Chem. 1985,57, 1788. 

With reference to this example, explain what you understand by the term isotope, b A sample of gallium contains 60% of atoms of 3iGa and 40% of atoms of jGa. Calculate the relative atomic mass of this sample of gallium. 

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