Is argon found more as a compound or element?
“Argon” is an element, atomic number 18 on periodic table. It is by definition an element. A compound is a chemical combination of various elements combined in very specific number ratios. What chemical compounds can be found in argon? Argon is an element.
Is argon a "ideal" gas?
Argon. Argon's most important chemical property is its inertness, which makes it an ideal protective gas – even at the high temperatures that are commonly encountered in metallurgy and arc welding. How can nitrogen gas be made to behave as an ideal gas?
Does argon react with any element or compound?
Argon is a noble gas and it does not react with any other element. It does not even react at high temperatures or under any other special conditions. One succeeded in producing only one argon compound that was very instable, under extremely low temperatures. Consequently, argon does not react with water.
What does argon combine with?
While it is replenished by outgassing, the atmospheric pressure today is less than 1% that of Earth's. And what little atmosphere it has is a toxic plume, composed predominantly of carbon dioxide, argon, and nitrogen, with traces of methane and water vapor. The atmosphere is not only unbreathable, but also incredibly thin.
Is argon an element or compound or molecule?
Argon is a chemical element with symbol Ar and atomic number 18. Classified as a noble gas, Argon is a gas at room temperature.
Why is argon not a compound?
All noble gases have full s and p outer electron shells (except helium, which has no p sublevel), and so do not form chemical compounds easily. Because of their high ionization energy and almost zero electron affinity, they were not expected to be reactive.
Is argon a molecule or atom?
Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in the Earth's atmosphere, at 0.934% (9340 ppmv)....ArgonAtomic number (Z)18Groupgroup 18 (noble gases)Periodperiod 3Blockp-block40 more rows
Does argon form a compound?
It's one of the inert gases that normally exist as single atoms. But in the 23 August issue of Nature, chemists report that they persuaded argon to mingle a little and form a compound with other elements. Argon--along with helium, neon, xenon, radon, and krypton--belongs to the so-called "noble" gases.
What is argon plasma coagulator?
The argon plasma coagulator is a device used for noncontact thermal coagulation of tissue. The device was first used in open and laparoscopic surgical procedures and in 1991 was adapted for use in endoscopy. Since then, argon plasma coagulation has expanded its clinical applications in the treatment of various gastrointestinal conditions. ...
Is argon a gas?
Argon is used as an inert gas shield in arc welding, as an inert gas to fill electric lamps, as a blanketing agent in metals refining (especial ly titanium and zirconium ), in ionization chambers and particle counters, and in doping semiconductors with controlled amounts of impurities.
Is argon a noncombustible gas?
Argon appears as a colorless odorless noncombustible gas. Heavier than air and can asphyxiate by displacement of air. Exposure of the container to prolonged heat or fire can cause it to rupture violently and rocket . If liquefied, contact of the very cold liquid with water may cause violent boiling.
Chemists form first known compound containing this "inert" gas
The element argon has always been a loner. It's one of the inert gases that normally exist as single atoms. But in the 23 August issue of Nature, chemists report that they persuaded argon to mingle a little and form a compound with other elements.
About the author
Alexander Hellemans is a freelance science writer in Antwerp, Belgium.
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Overview
Compounds
Argon's complete octet of electrons indicates full s and p subshells. This full valence shell makes argon very stable and extremely resistant to bonding with other elements. Before 1962, argon and the other noble gases were considered to be chemically inert and unable to form compounds; however, compounds of the heavier noble gases have since been synthesized. The first argon compou…
Characteristics
Argon has approximately the same solubility in water as oxygen and is 2.5 times more soluble in water than nitrogen. Argon is colorless, odorless, nonflammable and nontoxic as a solid, liquid or gas. 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 extr…
History
Argon (Greek ἀργόν, neuter singular form of ἀργός meaning "lazy" or "inactive") is named in reference to its chemical inactivity. This chemical property of this first noble gas to be discovered impressed the namers. An unreactive gas was suspected to be a component of air by Henry Cavendish in 1785.
Argon was first isolated from air in 1894 by Lord Rayleigh and Sir William Ramsay
Occurrence
Argon constitutes 0.934% by volume and 1.288% by mass of the Earth's atmosphere. Air is the primary industrial source of purified argon products. Argon is isolated from air by fractionation, most commonly by cryogenic fractional distillation, a process that also produces purified nitrogen, oxygen, neon, krypton and xenon. The Earth's crust and seawater contain 1.2 ppm and 0.45 ppm of argon, respectively.
Isotopes
The main isotopes of argon found on Earth are Ar (99.6%), Ar (0.34%), and Ar (0.06%). Naturally occurring K, with a half-life of 1.25×10 years, decays to stable Ar (11.2%) by electron capture or positron emission, and also to stable Ca (88.8%) by beta decay. These properties and ratios are used to determine the age of rocks by K–Ar dating.
In the Earth's atmosphere, Ar is made by cosmic ray activity, primarily by neutron capture of Ar fol…
Production
Argon is extracted industrially by the fractional distillation of liquid air in a cryogenic air separation unit; a process that separates liquid nitrogen, which boils at 77.3 K, from argon, which boils at 87.3 K, and liquid oxygen, which boils at 90.2 K. About 700,000 tonnes of argon are produced worldwide every year.
Ar, the most abundant isotope of argon, is produced by the decay of K with a half-life of 1.25×10 y…
Applications
Argon has several desirable properties:
• Argon is a chemically inert gas.
• Argon is the cheapest alternative when nitrogen is not sufficiently inert.
• Argon has low thermal conductivity.
Overview
Argon compounds, the chemical compounds that contain the element argon, are rarely encountered due to the inertness of the argon atom. However, compounds of argon have been detected in inert gas matrix isolation, cold gases, and plasmas, and molecular ions containing argon have been made and also detected in space. One solid interstitial compound of argon, Ar1C60 is stable at room temperature. Ar1C60 was discovered by the CSIRO.
Argonium
Argonium (ArH ) is an ion combining a proton and an argon atom. It is found in interstellar space in diffuse atomic hydrogen gas where the fraction of molecular hydrogen H2 is in the range of 0.0001 to 0.001.
Argonium is formed when H2 reacts with Ar atoms:
Ar + H 2 → ArH + H
Cluster argon cations
The diargon cation, Ar 2 has a binding energy of 1.29 eV.
The triargon cation Ar 3 is linear, but has one Ar−Ar bond shorter than the other. Bond lengths are 2.47 and 2.73 ångströms. The dissociation energy to Ar and Ar2 is 0.2 eV. In line with the molecule's asymmetry, the charge is calculated as +0.10, +0.58 and +0.32 on each argon atom, so that it greatly resembles Ar 2 bound to a neutral Ar atom.
Argon monohydride
Neutral argon hydride, also known as argon monohydride (ArH), was the first discovered noble gas hydride. J. W. C. Johns discovered an emission line of ArH at 767 nm and announced the find in 1970. The molecule was synthesized using X-ray irradiation of mixtures of argon with hydrogen-rich molecules such as H2, H2O, CH4 and CH3OH. The X-ray excited argon atoms are in the 4p state.
Argon polyhydrides
The argon dihydrogen cation ArH 2 has been predicted to exist and to be detectable in the interstellar medium. However it has not been detected as of 2021 . ArH 2 is predicted to be linear in the form Ar−H−H. The H−H distance is 0.94 Å. The dissociation barrier is only 2 kcal/mol (8 kJ/mol), and ArH 2 readily loses a hydrogen atom to yield ArH . The force constant of the ArH bond in this is 1.895 mdyne/Å (1.895×10 Pa).
Argoxonium
The argoxonium ion ArOH is predicted to be bent molecular geometry in the 1 A′ state. Σ is a triplet state 0.12 eV higher in energy, and A″ is a triplet state 0.18 eV higher. The Ar−O bond is predicted to be 1.684 Å long and to have a force constant of 2.988 mdyne/Å (2.988×10 Pa).
ArNH+
ArNH is a possible ionic molecule to detect in the lab, and in space, as the atoms that compose it are common. ArNH is predicted to be more weakly bound than ArOH , with a force constant in the Ar−N bond of 1.866 mdyne/Å (1.866×10 Pa). The angle at the nitrogen atom is predicted to be 97.116°. The Ar−N lengths should be 1.836 Å and the N−H bond length would be 1.046 Å
Argon dinitrogen cation
The argon dinitrogen linear cationic complex has also been detected in the lab:
Ar + N 2 → ArN 2 Ar + N2.
The dissociation yields Ar , as this is a higher-energy state. The binding energy is 1.19 eV. The molecule is linear. The distance between two nitrogen atoms is 1.1 Å. This distance is similar to that of neutral N2 rather than that of N 2 ion. The distance between one nitrogen and the argon …