Word: potassium
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...small, lemon-sized rock from the Ocean of Storms resembled an ordinary piece of granite, but it was, in fact, unlike any earthly specimen-or any of the other lunar material brought back by Apollo 12. It contained 20 times as much radioactive uranium, thorium and potassium as comparable amounts of other moon material and was the oldest lunar specimen yet obtained. Radioactive dating tests made by Caltech Geologist Gerald Wasserburg indicated that the rock was formed 4.6 billion years ago-around the time that the moon and the planets arc believed to have been created. Scientists hope that further...
Galya has had other interesting but troublesome relationships. Last June 18, a friend of hers, Gustav F. Ingwerson, a Denver inventor, painter and plastics designer, died of potassium cyanide poisoning. Ingwerson's will left less to his family than expected. He did bequeath small amounts of stock and an assortment of personal possessions-including a cuckoo clock, a color TV and a dinosaur bone-to Galya and her two children. Galya is now charged by Denver police with forging that will. She pleaded not guilty by reason of insanity...
...surprisingly, one of the few jubilant scientists in Houston last week was Geochemist Oliver Schaeffer, who led the team that calculated the age of the lunar material. He used potassium-argon dating, a method based on the rate at which radioactive potassium decays into argon (it takes 1.3 billion years for half the potassium to decay); as time passes, the ratio between the potassium and argon in a specimen changes at a known rate, thus revealing the approximate age of the sample. If there is any error at all, Schaeffer explains, he has underestimated the age of the rocks, because...
...addition to the argon that resulted from potassium decay, Schaeffer found an abundance of solar argon-and of helium and neon-that has collected during eons of bombardment by the sun. These particles were lodged only in the surface of the rocks, where they had remained undisturbed for hundreds of millions of years-more evidence that the moon's exterior has not undergone any recent upheavals...
Chemical analysis of the samples may also help determine whether lunar material was ever hot enough to have melted, or whether it has been relatively cool almost from the first. Moon specimens strikingly lacking in volatile elements such as potassium and arsenic could indicate that these substances had been expelled by high temperatures?and would support the theory of a volcanic moon. Those who believe that meteors gave the moon its cratered surface might still argue, however, that the volcanism had occurred only in areas struck?and heated?by huge meteors. Studies of the crystal size and average density...