Argon inert

Calcium is the second element of the fourth row. It has two electrons more than the argon inert gas population and these two electrons both occupy the 45 orbital ... 

Figure 9. Effect of processing time on the melt-flow index (MFI) of LDPE. (1) open chamber (excess air) (2) closed chamber (limited oxygen access) (3) closed chamber purged with argon (inert atmosphere).

Electrothermal atomizers for AES share many of the advantages associated with their use for AAS. The argon inert gas that prevents oxidation of the graphite tube ensures that minimal quenching occurs, although a number of other interferences may occur. By and large, the interferences are very similar to those experienced in traditional electrothermal AAS, such as carbide formation (for some analytes), scatter by particulate matter, and losses during thermal pretreatment. A more comprehensive overview of interferences may be found in the sections on AAS. The use of matrix modifiers to assist in the separation of the analyte from the matrix is still often necessary. 

CO2. laser ablation of a carbon rod (graphite pure or doped) at room temperature (no oven is needed) in an argon inert flow. A single continuous CO2 laser (wavelength 1064 nm power 400-900W) was directed to the above carbon target with the growth of carbon nanotubes. 

Argon is two and one half times as soluble in water as nitrogen, having about the same solubility as oxygen. Argon is colorless and odorless, both as a gas and liquid. Argon is considered to be a very inert gas and is not known to form true chemical compounds, as do krypton, xenon, and radon. 

Argon is frequently used for the determination of surface area, usually at 77 K. Like the other noble gases, argon is of course chemically inert and is composed of spherically symmetrical monatomic molecules. Argon stands in... 

A gun is used to direct a beam of fast-moving atoms or ions onto the liquid target (matrix). Figure 4.1 shows details of the operation of an atom gun. An inert gas is normally used for bombardment because it does not produce unwanted secondary species in the primary beam and avoids contaminating the gun and mass spectrometer. Helium, argon, and xenon have been used commonly, but the higher mass atoms are preferred for maximum yield of secondary ions. 

In this discussion, only inert gases such as argon or neon are used as examples because they are monatomic, which simplifies description of the excitation. The introduction of larger molecules into a discharge is discussed in later chapters concerning examination of samples by mass spectrometry. 

Precursor ions are selected by Ql and passed into the collision cell (Q2 orq2 of Figure 33.5). Here, collision with an inert gas (argon or helium) causes dissociation to occur, and the resulting fragment (product) ions are detected by scanning Q3 (Figure 33.6). 

Metallui ical. To prevent reaction with atmospheric oxygen and nitrogen, some metals must be shielded using an inert gas when heated or melted (94). AppHcations in metals processing account for most argon consumption and an important part of helium usage (see AfETALLURGY). 

In gas metal-arc, also called metal inert gas (MIG) welding, the arc is stmck between the workpiece and a metal electrode that is consumed as it is transferred in the form of molten droplets across the arc into the weld joint. Using a predominantiy argon shield gas, the droplets are transferred with Httie radial dispersion. Using pure helium, on the other hand, the droplets are larger and have more of a tendency to spray radially from the arc s axis. 

Finally, the metallisation layer usually requires patterning, which can be done by reactive ion etching (RIE) or back-sputtering. The two processes are similar. In both techniques accelerated ions hit the substrate and forcibly detach atoms or molecules from the surface. RIE uses reactive gases such as chlorine, Cl or trichlorofluoromethane [75-69-4] CCl E. Inert gases such as argon or neon are used in back-sputtering. 

Phenyllithium can be used as a solution in ethyl ether, but because of its limited stabUity (t 2 = 12 d at 35° C) it is commercially available in solution in mixtures, usuaUy 70 30 wt % cyclohexane ethyl ether (117). In this particular mixture of solvents, a 20 wt % solution, free of chlorobenzene, is stable for at least four months under an inert atmosphere (argon or nitrogen) in sealed containers at room temperature. Phenyllithium is also available in dibutyl ether solution (117). It is classified as a flammable Hquid. 

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