Atmosphere elements found

Scientists believe that the sulfur in Venus atmosphere came from volcanic eruptions. Earth has experienced its fair share of volcanic eruptions, too. However, the sulfur from early eruptions on Earth was incorporated into solid sulfur compounds. Indeed, sulfur is an important element found in many of the compounds that make up Earths crust. 

At room temperature and normal atmospheric pressure, all metals are solids except mercury, which is a liquid. Over 60% of the known elements are classified as metals, but of those only about 40 are of any economic importance. From this group, only a small number have been selected for discussion here. These are the metallic elements found most often in museum collections as manufactured items. Their properties are summarized in Table 2.7. 

Strontium is a naturally occurring element found in rocks, soil, dust, coal, and oil. Naturally occurring strontium is not radioactive and is referred to as stable strontium. Stable strontium in the environment exists in four stable isotopes, " Sr (read as strontium 84), Sr, Sr, and Sr. Twelve other unstable isotopes are known to exist. Its radioactive isotopes are Sr and °Sr. Strontium is chemically similar to calcium. It was discovered in 1790. The isotope Sr is a highly radioactive poison, and was present in fallout from atmospheric nuclear explosions and is created in nuclear reactors. Atmospheric tests of nuclear weapons in the 1950s resulted in deposits and contaminations. °Sr has a half-life of 28 years and is a high-energy beta emitter. Its common cationic salts are water soluble it forms chelates with compounds such as ethylenediaminetetraacetic acid strontium coordination compounds are not common. Powdered metallic strontium may constitute an explosion hazard when exposed to flame. 

If one assumes that other elements are transported by the atmosphere from urban centers in a manner similar to that of lead, and are subsequently deposited on the ocean surface and mixed vertically at a rate similar to that of lead, then the expected increase in ocean water concentrations of other elements can be calculated (Table 4). The most probable values show increases of 30% (Table 1) for several of the elements, although higher concentrations may exist. The values of the most probable increases suggest that trace elements in the surface layers bear little relationship to the concentration of elements found in organisms. The uptake of trace elements by the marine biota, however, does depend upon the chemical state of the elements, and we shall discuss this further in the later sections. 

Of approximately 80 elements found in soils, 17 are used by plants to grow. These are called the essential elements and include H, C, O, N, P, S, K, Mg, Ca, B, Cl, Mn, Fe, Cu, Zn, Mo, and Co. Hydrogen and O are derived from the hydrosphere, C from the atmosphere, N from the biosphere, and the remaining 13 from the lithosphere or the mineral soil. Soil is mainly an O-Si-Al-Fe matrix containing relatively small amounts of the other essential... 

On Earth, elements maybe found in the lithosphere (the rocky, solid part of Earth), the hydrosphere (the aqueous, or watery, part of Earth), or the atmosphere. Elements such as the noble gases, the rare earths, and commercially valuable metals like silver and gold occur in only trace quantities. Others, like oxygen, silicon, aluminum, iron, calcium, sodium, hydrogen, sulfur, and carbon are abundant. 

In 1859, Kirchofif made a breakthrough discovery about the nearest star—our sun. It had been known for some time that a number of narrow dark lines are found when sunlight is bent through a prism. These absences had been studied systematically by Fraunhofer, who also noted that dark lines can be found in the spectmm of other stars furthermore, many of these absences are found at the same wavelengths as those in the solar spectmm. By burning substances in the laboratory, Kirchoff was able to show that some of the features are due to the presence of sodium atoms in the solar atmosphere. For the first time, it had been demonstrated that an element found on our planet is not unique, but exists elsewhere in the universe. Perhaps most important, the field of modem spectroscopy was bom. 

Main mercury species in ambient air are elemental mercury (Hg°), reactive gaseous mercury (Hg(II)), mercury bound to aerosols, and methylmercury. Though dimethyl-mercury is together with Hg° the most volatile form of Hg, it has not been detected unequivocally in the atmosphere. Elemental mercury represents >95% of Hg in the atmosphere with ambient concentrations at the order of 1-5 ng m whereas MeHg in air was found to be in the range of 1 to 20 pg m (Pirrone et al. 2001). For this reason, in most cases mercury is pre-con-centrated on solid absorbers (gold, silver, activated carbon traps, etc.) prior to analysis (Drabaeck and Iverfeldt 1992, Horvat 1996). 

TABLE 8.6 Concentrations (ng m 3) and Size Distribution of Various Elements Found in Atmospheric Particles... 

Except for hydrogen, helium is the most abundant element found throughout the universe. Helium is extracted from natural gas. In fact, all natural gas contains at least trace quantities of helium. The fusion of hydrogen into helium provides the energy of the hydrogen bomb. The helium content of the atmosphere is about 1 part in 200,000. While it is present in various radioactive minerals as a decay product, the bulk of the Free World s supply is obtained from wells in Texas, Oklahoma, and Kansas. The only known helium extraction plants outside the United States in 1984 were in Eastern Europe (Poland), the USSR, and a few in India. 

Scientists recognized that an element s spectrum is like human fingerprints just as each person has unique fingerprints, each element in the periodic table has a unique spectrum. The spectrum of a compound is simply a combination of the spectra of the elements in that compound. The uniqueness of spectra makes them powerful analytical tools in the identification of the elements found in minerals, in biological samples, in Earth s atmosphere, and in the atmospheres of stars. Although much... 

The list of elements found in living matter is very different from those of the Earth s crust, oceans, and atmosphere. The major elements in living organisms are shown in Table 3.2. 

Atmospheric aerosols are small particulate matter with diameter of a few micrometer, which are caused by sandy dusts, smoke from factories, exhaust gas of cars and their deformed particles by photochemical reactions in the atmosphere. Elemental concentrations in atmospheric aerosol reflect air pollution and its generating process. The elements that may be found in dust samples range from hydrogen to uranium. However, the more common elements are H, C, N, O, F, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Co, Fe, Cu, Ni, Zn, Br, and Pb. While PIXE is generally used to determine concentrations of all elements with atomic number above Al Z = 13), the... 

AThe 92 elements found on Earth combine together in different ways. They make up the air in the atmosphere, the water in the sea, and the rocks beneath us. 

According to experiments performed under appropriate conditions, about 1% of the fission product iodine present in the flashed primary coolant volume is transported with the steam phase, about half of it in form of aerosols (Aim and Dreyer, 1980). This figure agrees well with that reported by Morell et al. (1985) and Hellmann et al. (1991), obtained in flashing experiments from small-diameter pipes (see Section 6.2.2.). In the experiments of Aim and Dreyer (1980), which were carried out in an uncoated steel vessel, only particulate iodide and elemental h were detected in the atmosphere of the vessel. The rate of plate-out of iodine from the atmosphere was found to depend on the specific geometric conditions of the experimental setup. In a comparatively small vessel, deposition halftimes of 8.5 hours for h and of 0.9 hours for aerosol iodide were measured within the first two hours after blowdown these values increased to 9.9 and 5.7 hours, respectively, during the following 22 hours. From other experiments markedly different values have been reported (e. g. CSE tests, see Section 7.3.S.3.8.). The reasons for these differences are not only due to the dimensions and true surface areas present in the respective experimental facility, but also to various other parameters, such as initial concentrations, turbulences in the atmosphere, rate of water droplet plate-out and of steam condensation. 

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