What is Argon?
Argon is the third element in the eighteenth column of the periodic table. It is classified as a noble gas. The argon atom has 18 electrons and 18 protons. Its outer shell is filled with eight electrons.
Characteristics and Properties
Under standard conditions, argon is an odorless and colorless gas. It is also an inert gas, which means it usually does not react with other elements to form compounds.
When argon is excited by a high-voltage electric field, it glows purple.
It has been found that argon forms a neutral compound with fluorine and hydrogen called argon fluorohydride (HArF). However, this compound is only stable at very cold temperatures (-256 degrees Celsius).
Highlights of Argon:
| Symbol | Ar |
| Atomic Number | 18 |
| Atomic Weight | 39.948 |
| Classification | Noble gas |
| Phase at Room Temperature | Gas |
| Density | 1.784 g/L @ 0°C |
| Melting Point | 189.35°C, -308.83°F |
| Boiling Point | 185.85°C, -302.53°F |
| Discovered by | Lord Rayleigh and Sir William Ramsay in 1894 |
Where is Argon found on Earth?
Argon is the most abundant noble gas in the Earth’s atmosphere. It makes up nearly 1% (0.94%) by volume of air, making it the third most abundant element in the air after nitrogen and oxygen. Argon is also found in trace amounts in the earth’s crust and seawater.
Argon is commonly produced from liquid air as a byproduct of nitrogen and oxygen production.
How is Argon used today?
Because argon is the rarest and least expensive gas, it is often used when an inert gas is required. One of the main uses of argon is as a gas inside incandescent lamps. Because argon does not react with the filament used by the bulb, even at high temperatures, argon helps the filament last longer and prevents the bulb glass from darkening.
Argon is also used for soldering, medical instruments, wine storage, window insulation, and microelectronics.
How was Argon discovered?
British chemist Henry Cavendish was the first scientist to show that air contains gases other than nitrogen, oxygen and carbon dioxide. However, he was unable to find or isolate another factor.
In 1894, British scientist Lord Rayleigh and Scottish chemist Sir William Ramsay began experimenting with other gases in the air. They eventually discovered argon as well as most other noble gases.
Where did Argon get its name?
The name argon comes from the Greek word “argos” which means “lazy” or “inactive”.
Isotopes
Argon has three stable isotopes, including argon-36, 38 and 40. By far, the majority (more than 99%) of argon found naturally on Earth is argon-40. The most common argon isotope in the universe is made by stars and is argon-36.
Interesting Facts about Argon
Argon has no known biological function.
When argon gas is combined with a small amount of mercury, it glows blue when electrically excited.
Large amounts of pure argon gas can be considered hazardous in enclosed areas because it is denser than air and causes people to suffocate.
When argon is used as a gas laser, it emits a blue-green color.
The argon gas present in the earth’s atmosphere comes from the radioactive decay of potassium.