Published in Chemistry World, 1 Mar 2011
What’s happened to the Earth’s missing xenon? For decades scientists have known that the abundance of xenon is curiously lower than predicted from comparisons with the other noble gases. Yet they have been unable to determine why. Now chemists in Canada have evidence that it is residing in the ground beneath our feet.
Some of the first hints of the anomaly came in the 1970s, when scientists found that xenon is about 20 times less abundant in our atmosphere than other noble gases – even though studies of meteorites suggested its general abundance in the Solar System should be roughly the same. Theories abounded: maybe the xenon has been lost into space, or frozen into the ice caps, or trapped inside sedimentary rock. But calculations showed that these processes could account for at best one-fifth of the missing gas. […]
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