 Discovery Information
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| Who: Sir William Ramsay, Baron Rayleigh |
| When: 1894 |
| Where: Scotland |
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| Name Origin
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| Greek: Argos (inactive). |
| "Argon" in different languages. |
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| Sources
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| Argon makes up 1% of the air and is isolated by removing nitrogen, oxygen, carbon dioxide and water from air. Argon is constantly being formed from the radioactive decay of radioactive potassium-40.
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| Abundance
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| Universe: 200 ppm (by weight) |
| Sun: 70 ppm (by weight) |
| Atmosphere: 9300 ppm |
| Earth's Crust: 1.2 ppm |
| Seawater: 0.45 ppm |
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| Uses
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| Argon is used for lighting, it is also used in plasma globes. It is also used to provide an inert atmosphere for certain projects
when explosion or other forms of oxidation may pose a problem. Also used in "Geiger" counters, which measure radiation levels.
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| Blue argon lasers are used in surgery to weld arteries, destroy tumors, and to correct eye defects. |
| Due to its inert qualities, it is commonly used by museum conservators to protect old materials or documents, which are prone
to gradual oxidisation in the presence of air.
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| Argon is used in the tires of luxury cars to protect the rubber from oxygen and to ensure quiet tires when the car moves at high speeds.
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| History
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| Argon was suspected to be present in air by Henry Cavendish in 1785 but was not discovered until 1894 by Lord Rayleigh and Sir William Ramsay in an experiment in which they removed all of the oxygen and nitrogen from a sample of air. Argon was also encountered in 1882 through independent research of H.F. Newall and W.N. Hartley. Each
observed new lines in the colour spectrum of air but were unable to identify the element responsible for the lines. Argon
became the first member of the noble gases to be discovered.
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| Up until 1957 the symbol for Argon was "A". |
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| Notes
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| Before 1962, argon and the other noble gases were generally considered to be chemically inert and not able to form compounds. However, since then, scientists have been able to force the heavier noble gases to form compounds. In 2000, the first argon compounds were formed by researchers at the University of Helsinki. By shining ultraviolet light onto frozen argon containing a small
amount of hydrogen fluoride, they were able to form argon hydrofluoride (HArF).
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| The Martian atmosphere contains 1.6% of argon-40 and 5 ppm of argon-36. In 2005, the Huygens probe also discovered the presence
of Ar-40 on Titan, the largest moon of Saturn.
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| Hazards
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| The gas presents a risk of asphyxiation if a large quantity is released into a room of small volume. |
