Search results
Results from the WOW.Com Content Network
The noble gases (helium, neon, argon, krypton, xenon and radon) were previously known as 'inert gases' because of their perceived lack of participation in any chemical reactions. The reason for this is that their outermost electron shells (valence shells) are completely filled, so that they have little tendency to gain or lose electrons.
Argon is colorless, odorless, nonflammable and nontoxic as a solid, liquid or gas. [11] Argon is chemically inert under most conditions and forms no confirmed stable compounds at room temperature. Although argon is a noble gas , it can form some compounds under various extreme conditions.
The term inert gas is context-dependent because several of the inert gases, including nitrogen and carbon dioxide, can be made to react under certain conditions. [1] [2] Purified argon gas is the most commonly used inert gas due to its high natural abundance (78.3% N 2, 1% Ar in air) [3] and low relative cost.
It is the least reactive of the noble gases; no normal compounds of neon have so far been synthesised. A small piece of rapidly melting solid argon. Argon has a density of 1.784 × 10 −3 g/cm 3, liquifies at −185.848 °C, and solidifies at −189.34 °C. Although non-toxic, it is 38% denser than air and therefore considered a dangerous ...
Cooled argon gas can form clusters of atoms. Diargon, also known as the argon dimer, has a binding energy of 0.012 eV, but the Ar 13 and Ar 19 clusters have a sublimation energy (per atom) of 0.06 eV. For liquid argon, which could be written as Ar ∞, the energy increases to 0.08 eV. Clusters of up to several hundred argon atoms have been ...
In many applications, the noble gases are used to provide an inert atmosphere. Argon is used in the synthesis of air-sensitive compounds that are sensitive to nitrogen. Solid argon is also used for the study of very unstable compounds, such as reactive intermediates, by trapping them in an inert matrix at very low temperatures. [91]
A nitrogen generator Bottle of 4Å molecular sieves. Pressure swing adsorption provides separation of oxygen or nitrogen from air without liquefaction. The process operates around ambient temperature; a zeolite (molecular sponge) is exposed to high pressure air, then the air is released and an adsorbed film of the desired gas is released.
Many gases can be put into a liquid state at normal atmospheric pressure by simple cooling; a few, such as carbon dioxide, require pressurization as well. Liquefaction is used for analyzing the fundamental properties of gas molecules (intermolecular forces), or for the storage of gases, for example: LPG, and in refrigeration and air conditioning.