Argon

Argon ice 1

Isolation of Argon

Lord Rayleigh Vanity Fair 21 December 1899

Argon-fluorohydride-3D-vdW

Argon

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), making it more common than carbon dioxide. It is completely inert under most conditions and forms no confirmed stable compounds at room temperature.

Properties

Argon is a colorless, odorless, tasteless, and nontoxic gas at room temperature and pressure. Being a noble gas, it is characterized by its lack of chemical reactivity, particularly under standard conditions. It has a boiling point of −185.848 °C (−302.526 °F) and a melting point of −189.34 °C (−308.81 °F), which makes it ideal for use in a variety of industrial processes that require a non-reactive atmosphere.

Discovery and History

Argon was first isolated in 1894 by Lord Rayleigh and Sir William Ramsay in London by removing nitrogen, oxygen, water, and carbon dioxide from clean air. They discovered a new component of air that would not react with anything. The name "argon" is derived from the Greek word άργον, meaning "lazy" or "inactive", reflecting its inert nature.

Production

Commercially, argon is produced as a byproduct of the production of oxygen and nitrogen from air for industrial use. Air is liquefied and then fractionally distilled to separate out the argon, which accumulates as a result of its boiling point being between those of oxygen and nitrogen.

Uses

Argon's primary use is to provide an inert atmosphere in high-temperature industrial processes such as arc welding, in the production of titanium and other reactive elements, and in the manufacture of silicon and germanium semiconductors. It is also used in the bulbs of incandescent light bulbs to protect the filament from oxidation, and in double glazing windows to improve insulation. Additionally, argon is used in scientific research, for example, in argon dating to determine the age of rocks and minerals.

Safety

Argon is considered to be non-toxic and primarily poses a threat when it displaces oxygen in the air, potentially leading to suffocation. Proper ventilation in areas where argon is used is necessary to prevent asphyxiation.

Environmental Impact

Argon is environmentally benign, as it is inert and does not react with other elements or compounds. It does not contribute to greenhouse gas emissions or ozone depletion.