Argon is also used in fluorescent glow starters.Ī small piece of rapidly melting solid argonĪrgon has approximately the same solubility in water as oxygen and is 2.5 times more soluble in water than nitrogen. Argon makes a distinctive blue-green gas laser. Argon is also used in incandescent, fluorescent lighting, and other gas-discharge tubes. Argon is mostly used as an inert shielding gas in welding and other high-temperature industrial processes where ordinarily unreactive substances become reactive for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Its triple point temperature of 83.8058 K is a defining fixed point in the International Temperature Scale of 1990.Īrgon is extracted industrially by the fractional distillation of liquid air. The complete octet (eight electrons) in the outer atomic shell makes argon stable and resistant to bonding with other elements. The name "argon" is derived from the Greek word ἀργόν, neuter singular form of ἀργός meaning 'lazy' or 'inactive', as a reference to the fact that the element undergoes almost no chemical reactions. In the universe, argon-36 is by far the most common argon isotope, as it is the most easily produced by stellar nucleosynthesis in supernovas. Nearly all of the argon in Earth's atmosphere is radiogenic argon-40, derived from the decay of potassium-40 in Earth's crust. Argon is the most abundant noble gas in Earth's crust, comprising 0.00015% of the crust. It is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 times as abundant as carbon dioxide (400 ppmv), and more than 500 times as abundant as neon (18 ppmv). Argon is the third-most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is in group 18 of the periodic table and is a noble gas.
A 34, 5123 (1986).Argon is a chemical element with the symbol Ar and atomic number 18.
#Argon atomic emission spectrum free#
Karaziya, Introduction to the Theory of X-Ray and Electronic Spectra of Free Atoms (Mokslas, Vilnus, 1987). Amus’ya, The Photoelectric Effect in Atoms (Nauka, Moscow, 1987).Ī. Tulkki, in Atomic Inner-Shell Physics, Ed. The calculation results have a predictive character and, for the case of the incident photon energies of 3199.9 eV, they are in good agreement with the results of the synchrotron experiment on measuring the X-ray Kβ emission spectrum of a free Ar atom. The effects of the radial relaxation of electron shells, the correlation loosening, vacuum correlations, the spin-orbit and multiplet splitting, as well as the Auger and radiative decays of the vacancies produced are taken into account. The calculations are performed in the nonrelativistic Hartree-Fock approximation for the wave functions of one-electron states and in the dipole approximation for the anomalous-dispersion amplitude of the scattering probability. The evolution of the spatially extended profile of the scattering cross section to the principal Kβ 1,3 and satellite Kβ 5 structures of the Ar X-ray Kβ emission spectrum is demonstrated. The influence of many-particle effects on absolute values and the shape of the doubly differential cross section of resonant inelastic scattering of a linearly polarized X-ray photon by a free Ar atom close to the K- and KM 23-ionization thresholds is studied theoretically.
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