Argon
Appearance
Argon is a colourless, odourless gas that is totally inert to other substances.
Uses
Argon is often used when an inert atmosphere is needed. It is used in this way for the production of titanium and other reactive elements. It is also used by welders to protect the weld area and in incandescent light bulbs to stop oxygen from corroding the filament.
Argon is used in fluorescent tubes and low-energy light bulbs. A low-energy light bulb often contains argon gas and mercury. When it is switched on an electric discharge passes through the gas, generating UV light. The coating on the inside surface of the bulb is activated by the UV light and it glows brightly.
Double-glazed windows use argon to fill the space between the panes. The tyres of luxury cars can contain argon to protect the rubber and reduce road noise.
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Element Facts & Figures
| Atomic Symbol | Ar |
| Atomic Number | 92 |
| Atomic Weight | 238.029 |
| Melting Point | −189.34°C, −308.81°F, 83.81 K |
| Boiling Point | −185.848°C, −302.526°F, 87.302 K |
| Phase at Room Temperature | Gas |
| Element Classification | Noble Gas |
| Period Number | 3 |
| Group | 18 |
Biological role
Argon has no known biological role.
The average human body contains about 3 milligrams of fluoride. Too much fluoride is toxic. Elemental fluorine is highly toxic.
Natural abundance
Argon makes up 0.94% of the Earth’s atmosphere and is the third most abundant atmospheric gas. Levels have gradually increased since the Earth was formed because radioactive potassium-40 turns into argon as it decays. Argon is obtained commercially by the distillation of liquid air.