Argon

Argon, with the atomic number 18, is a chemical element belonging to group 18 of the periodic table and is the third most abundant gas in Earth’s atmosphere. This non-combustible, colourless, and odourless gas has a molecular formula of Ar and a density higher than air. Argon is commonly used in monatomic form in fluorescent tubes.

1.0Introduction

Argon was the first noble gas identified by scientists. In 1894, Scottish chemist William Ramsay and English physicist Lord Rayleigh discovered argon’s existence. The name "argon" comes from the Greek word "argos," meaning "inactive" or "lazy," reflecting its inert nature.

Argon belongs to the noble gas family and makes up about 0.93% of Earth’s atmosphere, making it the third most abundant gas in our environment. Noble gases like argon are known for being non-flammable, cryogenic, and chemically unreactive.

2.0Physical  Properties of Argon

3.0Chemical Properties of Argon

When heated, argon emits a blue-violet glow. Argon lasers produce a characteristic blue-green light. Due to its complete valence electron shell, argon is chemically inert, typically in the 0 oxidation state.

• Compound Formation: Noble gases like argon are generally non-reactive, making argon compounds rare. However, argon fluorohydride (HArF) has been observed at temperatures below 17 K. At standard conditions, argon compounds are not stable.
• Clathrate Formation: Argon can form clathrates with water, where argon atoms are trapped within water molecules. Ions like ArH⁺ and complexes in the excited state, such as ArF, have also been identified.
• Potential for Compounds: Although stable argon compounds have not yet been synthesised at room temperature, theoretical research suggests they might be possible.

4.0Uses of Argon

• Inert Atmosphere Applications: Argon produces reactive elements like titanium and protects welding areas from atmospheric gases that could compromise the weld.
• Lighting: Argon prevents filament oxidation in incandescent light bulbs. In fluorescent tubes and low-energy bulbs, argon and mercury generate UV light, activating the phosphorescent coating to produce bright light.
• Insulation: Argon is used in double-glazed windows to fill the space between panes, improving insulation by reducing heat transfer.
• Vehicle tyres: Argon is sometimes used in the tyres of luxury cars to protect the rubber and reduce road noise.
• Medical Lasers: Argon lasers emit blue-green light used in dermatology for targeting blood vessels, while argon-dye lasers provide precise wavelengths for eye surgeries, treating conditions like retinal issues and tumours.