Gallium abundance

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 ... 

Cells made from GaAs are more costly than silicon cells, because the production process is not as well developed, and gallium and arsenic are not abundant materials. GaAs cells have been used when very high efficiency is needed regardless of cost such as required in space applications. They were also used in the Sunraycer, a photovoltaic-powered electric car, which won the Pentax World Solar Challenge race for solar-powered vehicles in 1987. It ran the 3000-km from Darwin to Adelaide, Australia at an average day time speed of 66-km per hour. The 1990 race was won by a... 

The mass spectrometric behavior (the types and abundance ratios of the fragments) shows variations from compound to compound depending on the changes of both the metal and halogen atoms. Substitution of aluminium by gallium or that of chlorine by bromine considerably decreases the stability of the molecular ion. 

GaUium is widely distributed in nature, mostly found in trace amounts in many minerals including sphalerite, diaspore, bauxite, and germanite. It is found in aU aluminum ores. Gallium sulfide occurs in several zinc and germanium ores in trace amounts. It also is often found in flue dusts from burning coal. Abundance of this element in the earth s crust is about 19 mg/kg. Its average concentration in sea water is 30 ng/L. 

Metallic liquids can also experience fractional crystallization. The abundances of trace elements such as gold, gallium, germanium, and iridium and the major element nickel in various classes of iron meteorites vary because of the separation of crystalline metal phases (kamacite or taenite). 

Time of flight ion probes (TOF SIMS) have unique capabilities not found in other mass spectrometers. A pulsed ion beam, typically either cesium or gallium, ejects atoms and molecules from the sample. Ionized species are accelerated down the flight tube and the arrival time in the detector is recorded, giving the mass of the species (see discussion of time-of-flight mass analyzers above). TOF SIMS instruments used in cosmochemistry have spatial resolutions of <1 pm. They are used to determine elemental abundances in IDPs and Stardust samples. The spatial distribution of elements within a small sample can also be determined. TOF SIMS instruments can obtain good data with very little consumption of sample. 

The results are shown in Tables I, II, and III. The major elements in coal and in the derived products are, in order of decreasing abundance in the materials studied, silicon, aluminum, calcium, iron, and magnesium. With the minor and trace elements, the detection limits vary with the ash content of each type of material about 1-5 ppm for the coals and residues and 1-3 ppb for the oils. The elements thallium, bismuth, germanium, and gallium were sought but not detected. 

Gallium is more abundant than lead in the Earth s crust so it is unlikely there would ever be a shortage... 

The mass-69 isotope,69Ga, is the more abundant (60.11%) of the two stable isotopes of gallium. It has... 

The isotopes of gallium have the following relative abundances Ga-69, 60.0% and Ga-71, 40.0%. Estimate the average atomic mass of gallium using the mass numbers of the isotopes. 

The elements below boron in Group IIIA of the periodic table include one of the most common and useful metals and three others that are much less important. Aluminum is the third most abundant element, and it occurs naturally in a wide variety of aluminosilicates, some of which will be described in more detail in Chapter 11. It also occurs in the minerals bauxite, which is largely AIO(OH), and cryolite, Na3AlF6. Although a few relatively rare minerals contain gallium, indium, and thallium, they are usually found in small quantities and are widely distributed. As a result, these elements are generally obtained as by-products in the smelting of other metals, especially zinc and lead. 

Gallium is very much less abundant than aluminum and tends to occur at low concentrations in snlfide minerals rather... 

The two naturally occurring isotopes of Gallium Table 2 can be used as an aid in mass spectroscopic studies. Isotopic distribution patterns have been used to model the masses and abundances of the isotopes for a given formula, and as a fingerprinting tool when used in a comparative analysis with the experimental data. This technique has recently been used for identifying the formation, mechanism, and the fragmentation pattern of Ga clusters (Figure 2), and more recently to confirm the formation of the first Ga=As... 

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