This sudden expansion absorbs heat from the coils, cooling the compressed air. The process of compression and expansion is repeated until most of the gases present in the air are transformed into liquids.
They soon discovered that the atmospheric nitrogen was mixed with a small amount of an unknown substance. By using magnesium to absorb the nitrogen, they were able to isolate the substance, which they named argon, from the Greek word argos inactive , because it did not react with other substances. In , Ramsay and his assistant Morris William Travers discovered that the mineral clevite released argon and helium when heated. This was the first time helium was detected on Earth.
In , Ramsay and Travers obtained three new elements from air, which had been cooled into a liquid. They named these elements krypton, from the Greek word kryptos hidden ; neon, from the Greek word neos new ; and xenon, from the Greek word xenos strange.
In , the German chemist Friedrich Dom noted that the radioactive element radium released helium and an unknown radioactive gas as it decayed. In , Ramsay and his assistant Robert Whytlaw-Gray determined the density of this unknown gas and named it niton, from the Latin word nitere to shine , because its radioactivity caused it to glow when cooled to a liquid.
Niton, later known as radon, was the last noble gas to be discovered. In , Ramsay was awarded the Nobel Prize in Chemistry for his research of noble gases.
The noble gases were formerly known as the rare gases or the inert gases. It was later shown that some were quite common and that some were not completely unreactive. In , Neil Bartlett created xenon platinum hexafluoride, the first chemical compound of a noble gas. Compounds of radon were created in the same year and compounds of krypton in No longer thought of as rare or inert, these elements came to be known as the noble gases.
Like the so-called noble metals gold, silver, platinum, etc. Krypton played an important role in science from , when the length of the meter was defined as 1,, The meter was later defined in terms of the speed of light in a vacuum, but krypton continues to be used in scientific research.
In order to separate krypton, as well as the other gases, from the liquid air, the air is slowly warmed in a process called fractional distillation. Operating under the assumption that each liquid has its own distinct temperature at which it changes to a gas, fractional distillation separates the gases within air one at a time.
Although traces of krypton are found in various minerals, the most important source of krypton is Earth's atmosphere. Air is also the most important source for the other noble gases, with the exception of helium obtained from natural gas and radon obtained as a byproduct of the decay of radioactive elements.
At sea level, dry air contains It also contains 0. Other components of dry air include carbon dioxide, hydrogen, methane, nitric oxide, and ozone. Krypton can also be obtained from the fission of uranium, which occurs in nuclear power plants. Unlike air, which contains only the stable isotopes of krypton, this process produces both stable isotopes and radioactive isotopes of krypton. The most important factor in the quality control of krypton production is ensuring that the final product contains only krypton.
The process of fraction distillation has been developed to the point where it produces very pure products from air, including krypton. Random samples of krypton are tested for purity by spectroscopic analysis.
This process involves heating a substance until it emits light. The light then passes through a prism or a grating in order to produce a spectrum, in the same way that sunlight produces a rainbow. Next Element Rubidium. What's in a name? From the Greek word for hidden, kryptos. Travers, an English chemist, while studying liquefied air. Small amounts of liquid krypton remained behind after the more volatile components of liquid air had boiled away.
The earth's atmosphere is about 0. The high cost of obtaining krypton from the air has limited its practical applications. The oldest Antarctic ice ever found fell as snow , years ago. Bubbles in the ice trap atmospheric gases as they were when the snow fell, Buizert told Live Science.
By measuring the levels of krypton and comparing them to the current atmosphere, researchers can use the known rate of decay of the isotope to determine the ice's age. The krypton measurement technique is only about a decade old, Buizert said. Because krypton and krypton in general is quite rare in the atmosphere, using the gas for dating requires a lot of material — lbs.
The actual sampling of the ice was done only two years before the paper was published, Buizert said. Since then, the technology has improved so much that only 44 lbs. Researchers are now seeking even older ice in Antarctica, hoping to find some dating back as far as 1.
These ice samples hold clues about the ancient climate and atmosphere at the time when the snow fell.
Far from the glaciers of Antarctica, krypton has also been used to date amazing old groundwater in the Sahara Desert. A study in the journal Geophysical Research Letters revealed that in certain areas of southwestern Egypt, the groundwater reaching the surface hasn't seen the light of day for 1 million years.
Another isotope of krypton, krypton, is largely produced as a byproduct of nuclear fission. By measuring levels of krypton in the atmosphere over secretive countries like North Korea, researchers can pinpoint locations that might harbor hidden nuclear facilities. In , for example, the BBC reported that sensors along the North Korean border had noted high levels of krypton that did not emanate from the country's main nuclear plant — suggest a second, secret plant.
North Korea tested nuclear bombs in , and , according to the nonprofit Nuclear Threat Initiative.
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