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Ar contamination. Most of the argon in Earth's atmosphere was produced by electron capture of long-lived 40 K (40 K + e − → 40 Ar + ν) present in natural potassium within Earth. The 39 Ar activity in the atmosphere is maintained by cosmogenic production through the knockout reaction 40 Ar (n,2n) 39 Ar and similar reactions. The half-life of 39
Kinetic diameter is a measure applied to atoms and molecules that expresses the likelihood that a molecule in a gas will collide with another molecule. It is an indication of the size of the molecule as a target.
Argon–argon (or 40 Ar/ 39 Ar) dating is a radiometric dating method invented to supersede potassium–argon (K/Ar) dating in accuracy. The older method required splitting samples into two for separate potassium and argon measurements, while the newer method requires only one rock fragment or mineral grain and uses a single measurement of argon isotopes.
Despite the trapping of 40 Ar in many rocks, it can be released by melting, grinding, and diffusion. Almost all argon in the Earth's atmosphere is the product of 40 K decay, since 99.6% of Earth's atmospheric argon is 40 Ar, whereas in the Sun and presumably in primordial star-forming clouds, argon consists of < 15% 38 Ar and mostly (85%) 36 Ar.
C-25 (75% argon/25% CO 2) is commonly used by hobbyists and in small-scale production. Limited to short circuit and globular transfer welding. Common for short-circuit gas metal arc welding of low carbon steel. C-20 (80% argon/20% CO 2) is used for short-circuiting and spray transfer of carbon steel.
A buffer gas usually consists of atomically inert gases such as helium, [1] [2] argon, or nitrogen. [3] Krypton , neon , and xenon are also used, primarily for lighting. [ citation needed ] In most scenarios, buffer gases are used in conjunction with other molecules for the main purpose of causing collisions with the other co-existing molecules.
The decarburization step is controlled by ratios of oxygen to argon or nitrogen to remove the carbon from the metal bath. The ratios can be done in any number of phases to facilitate the reaction. The gases are usually blown through a top lance (oxygen only) and tuyeres in the sides/bottom (oxygen with an inert gas shroud).
A cryogenic gas plant is an industrial facility that creates molecular oxygen, molecular nitrogen, argon, krypton, helium, and xenon at relatively high purity. [1] As air is made up of nitrogen, the most common gas in the atmosphere, at 78%, with oxygen at 19%, and argon at 1%, with trace gasses making up the rest, cryogenic gas plants separate air inside a distillation column at cryogenic ...