potassium-40


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potassium-40

[pə′tas·ē·əm ¦fȯr·dē]
(nuclear physics)
A radioactive isotope of potassium having a mass number of 40, a half-life of approximately 1.31 × 109 years, and an atomic abundance of 0.000122 gram per gram of potassium.
References in periodicals archive ?
Kao Chin said the report issued by the AEC's Radiation Monitoring Center earlier in September discovered that among 18 samplings of edible salts that were tested, Taiyen's three salt substitutes, Dietary Salt, Delicious Salt, and Natural Flavor Salt, contain high doses of Potassium-40 - 8,860 becquerel/kilometer (Bq/Kg), 5,063 Bq/Kg, and 5,063 Bq/Kg respectively - compared to other salt products sold in the domestic or global market.
FOOD p15 bananas are radioactive because they contain high amounts of potassium-40, but have to eat 400 a day up the levels would cause serious damange.
Naturally occurring radionuclides, such as potassium-40, polonium-210, thorium-232 and uranium-238 can be present in food and drinking water in measureable quantities.
Polonium-210 and potassium-40 are naturally occurring radioisotopes in the ocean, for example.
MEASUREMENTS: FFM, ASMM, FM, and percentage fat mass by whole-body dual-energy x-ray absorptiometry; TBK, BCM, and TBK/FFM ratio by whole body potassium-40 counter.
While a kilogram of dried bluefin tuna that migrated after the Fukushima accident had an average of 4 becquerels (bq) of cesium-134 and 6.3 bq of cesium-137, they also had an average of 347 bq of naturally occurring potassium-40. (A becquerel is a standard measurement for radiation output; radiation
(This technique is also used with other radioisotopes, including potassium-40 and uranium-235.)
Stevenson points out that all the geoneutrino detectors proposed share a shortcoming: They can't detect the geoneutrinos coming from radioactive potassium-40. These geoneutrinos have too little energy to trigger the detector.
We also have some potassium-40 in our bones and organs--half-life 1,300 million years.
29: The isotopes potassium-40 and argon-40 are particularly important together in which scientific technique?
Potassium-40 1.5 x [10.sup.-12] 1.3 x [10.sup.9] years
Within the salt crystals the team found traces of xenon-129, an isotope most commonly formed by the radioactive decay of iodine-129, and argon-40, a decay product of potassium-40. Analysis of these implies that the salt crystals are 4.571 billion years old, dating to within just a few million years of the oldest known solar-system minerals.

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