potassium-40


Also found in: Encyclopedia.

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.
Mentioned in ?
References in periodicals archive ?
Taiyen later released a statement quoting the response of the AEC that the tested Potassium-40 is a source of natural radioactivity often found in animal and human bodies.
Taiyen responds to accusation that its salt substitutes contain high levels of radiation
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.
How is Fukushima's fallout affecting marine life?
And although only a tiny fraction of potassium-40 is actually radioactive, and most of it has already decayed over Earth's 4.6-billion-year history, potassium still contribute up to 20 percent of the radioactive heat, Stevenson says.
Geoneutrinos: for a big view of inner Earth, catch a few ..
For that far back, you need to measure the decay of such things as Uranium-235 or Potassium-40.
How to become an old fossil
Muscle potassium-40 mean activity (n = 65) was 83.0 Bq/kg, and varied significantly from 76.0 to 104.4 Bq/kg among locations.
Radionuclide levels in caribou of Northern Alaska in 1995-96
Emissions of potassium-40, a radioactive form of the element occurring naturally in the body in tiny amounts, measure mostly muscle mass, because at least 70 percent of body potassium is in the muscle, says Ellis.
Scanning for growth trends
spectrometric measurements taken soil samples (264 samples), using semiconductor gamma spectrometry approved by the President of the NAEA, to mark the samples tested concentrations of cesium-137 and natural radionuclides (radium-226, actinium-228, potassium-40).
Monitoring of radiation carried out in the framework of the state environmental monitoring
An isotope of argon called argon-40 is produced from the natural decay of potassium-40. A common technique for determining a rock's age is to heat the rock and measure the amount of argon-40 released: The more argon-40, the older a rock may be.
Vesta becomes smallest known planetary object to have generated dynamo
Yet they were still below levels of concern for humans and marine organisms and were about one-sixth the level of radiation that marine organisms receive from naturally occurring radionuclides such as potassium-40.
Lessons from Fukushima: what have scientists learned about the causes and consequences of the 2011 earthquake and tsunami in Japan?
However, in 1999, using potassium-40 atoms, Jin and her colleagues achieved a key milestone toward making a fermionic-type condensate (SN: 9/11/.99, p.
Extreme impersonations: frigid atomic clouds mimic neutron stars, exotic superconductors, and the newborn universe
(Argon-40 results from the decay of radioactive potassium-40, which has a half-life of 1.3 billion years; the argon accumulates at a predictable rate after each droplet solidifies into glass.)
A Recent Rush of Impacts?
In their experiments at JILA, DeMarco and Jin magnetically trapped batches of about 100 million atoms of potassium-40. Their method of reducing the temperature resembles the cooling of a cup of coffee.
When the other half gets really cold

Medical browser ?
Full browser ?