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.

The complete octet (eight electrons) in the outer atomic shell makes argon stable and resistant to bonding with other elements.

[11] Argon is chemically inert under most conditions and forms no confirmed stable compounds at room temperature.

They trapped a mixture of atmospheric air with additional oxygen in a test-tube (A) upside-down over a large quantity of dilute alkali solution (B), which in Cavendish's original experiment was potassium hydroxide,[18] and conveyed a current through wires insulated by U-shaped glass tubes (CC) which sealed around the platinum wire electrodes, leaving the ends of the wires (DD) exposed to the gas and insulated from the alkali solution.

The arc was powered by a battery of five Grove cells and a Ruhmkorff coil of medium size.

The remaining oxygen was reacted with alkaline pyrogallate to leave behind an apparently non-reactive gas which they called argon.

[25][26] In Earth's atmosphere, 39Ar is made by cosmic ray activity, primarily by neutron capture of 40Ar followed by two-neutron emission.

37Ar is created from the neutron capture by 40Ca followed by an alpha particle emission as a result of subsurface nuclear explosions.

The atmospheres of Mars, Mercury and Titan (the largest moon of Saturn) contain argon, predominantly as 40Ar.

Mendeleev positioned the elements on his periodic table in order of atomic weight, but the inertness of argon suggested a placement before the reactive alkali metal.

This full valence shell makes argon very stable and extremely resistant to bonding with other elements.

Argon is used in the poultry industry to asphyxiate birds, either for mass culling following disease outbreaks, or as a means of slaughter more humane than electric stunning.

Argon is denser than air and displaces oxygen close to the ground during inert gas asphyxiation.

[36] Its non-reactive nature makes it suitable in a food product, and since it replaces oxygen within the dead bird, argon also enhances shelf life.

The interaction between the hypothetical WIMPs and an argon nucleus produces scintillation light that is detected by photomultiplier tubes.

Two-phase detectors containing argon gas are used to detect the ionized electrons produced during the WIMP–nucleus scattering.

[40] Dark-matter detectors currently operating with liquid argon include DarkSide, WArP, ArDM, microCLEAN and DEAP.

At Linköping University, Sweden, the inert gas is being utilized in a vacuum chamber in which plasma is introduced to ionize metallic films.

[42] In winemaking, argon is used in a variety of activities to provide a barrier against oxygen at the liquid surface, which can spoil wine by fueling both microbial metabolism (as with acetic acid bacteria) and standard redox chemistry.

Argon is also used as a preservative for such products as varnish, polyurethane, and paint, by displacing air to prepare a container for storage.

Argon gas is also commonly used for sputter deposition of thin films as in microelectronics and for wafer cleaning in microfabrication.

[45] Blue argon lasers are used in surgery to weld arteries, destroy tumors, and correct eye defects.

It is used for the specific way it ionizes and emits light, such as in plasma globes and calorimetry in experimental particle physics.

[47] Argon is also used in technical scuba diving to inflate a dry suit because it is inert and has low thermal conductivity.

[49] Argon-39, with a half-life of 269 years, has been used for a number of applications, primarily ice core and ground water dating.

In 2014, the World Anti-Doping Agency (WADA) added argon and xenon to the list of prohibited substances and methods, although at this time there is no reliable test for abuse.

A 1994 incident, in which a man was asphyxiated after entering an argon-filled section of oil pipe under construction in Alaska, highlights the dangers of argon tank leakage in confined spaces and emphasizes the need for proper use, storage and handling.