potassium-40


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potassium-40

n.
A naturally occurring beta-emitting radioactive isotope of potassium having a half-life of 1.3 billion years; it is the chief source of natural radioactivity of living tissue.
References in periodicals archive ?
In all cases, however, the amounts of cesium and silver isotopes were much lower than those of naturally occurring potassium-40 in the same samples.
In bluefin tuna caught off San Diego, the total radioactive cesium levels were 10 becquerels, only three percent above radiation levels from naturally occurring potassium-40, and far below safe-consumption levels set by the United States and Japanese governments.
And although only a tiny fraction of potassium-40 is actually radioactive, and most of it has already decayed over Earth's 4.
Though serious, these totals pale compared to the abundance of radioactive substances naturally present in seawater such as uranium-238 and potassium-40.
However, in 1999, using potassium-40 atoms, Jin and her colleagues achieved a key milestone toward making a fermionic-type condensate (SN: 9/11/.
In their experiments at JILA, DeMarco and Jin magnetically trapped batches of about 100 million atoms of potassium-40.
To date the rocks, Swisher's group used a radiometric technique that relies on the radioactive decay of potassium-40 to argon-40 over millions of years.
has used the radioactive decay of potassium-40 into argon-40 to date lava flows from Lathrop Wells and the California cone.
Another explanation of the vent light migh involve something called Cherenkov radiation, which comes from radioactive elements such as potassium-40.

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