Then it changes from a liquid to a solid at -189.3°C (-308.7°F).Argon can be produced from liquid air by fractional distillation.The spectrum (plural: spectra) of an element consists of a series of colored lines and is different for every element.Ramsay studied the spectrum of the unidentified gas.Argon is also used in making "neon" lamps and in lasers. However, English scientist Henry Cavendish (1731-1810) had predicted the existence of argon 200 years earlier.When Cavendish removed oxygen and nitrogen from air, he found that a very small amount of gas remained.
This method of dating rocks is described in the potassium entry.Argon is used to provide an inert blanket for certain industrial operations.An inert blanket of gas prevents any chemicals in the operation from reacting with oxygen and other substances present in air.These particles stick in the atoms and make them radioactive.No radioactive isotopes of argon have any practical application.The noble gases are sometimes called inert gases because Group 18 (VIIIA) elements react with very few other elements.In fact, no compound of argon has ever been produced.The two scientists decided to make their announcement together.The name argon comes from the Greek word argos, "the lazy one." The name is based on argon's inability to react with anything. At the time, the table ended with Group 17 (VIIA) at the right.But Ramsay had an advantage over Cavendish: he could use spectroscopy, which did not exist in Cavendish's time.Spectroscopy is the process of analyzing light produced when an element is heated.