Potassium argon radioactive dating

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This isotope makes up one ten thousandth of the potassium found naturally.

In terms of atomic weight, it is located between two more stable and far more abundant isotopes (potassium 39 and potassium 41) that make up 93.25% and 6.73% of the Earth total potassium supply respectively.

This 1.46 Me V gamma ray is important, as it allows us to identify when potassium 40 decays.

The beta electrons of the decay into calcium 40 (89.3% of the time) are not accompanied by gamma rays, and are generally absorbed into the medium they find themselves in.When an atom of potassium 40 decays into argon 40, the argon atom produced is trapped by the crystalline structure of the lava.It can only escape when the rock is in its molten state, and so the amount of fossilized argon present in lava allows scientists to date the age of the solidification.DR Potassium 40 is a radioisotope that can be found in trace amounts in natural potassium, is at the origin of more than half of the human body activity: undergoing between 4 and 5,000 decays every second for an 80kg man.Along with uranium and thorium, potassium contributes to the natural radioactivity of rocks and hence to the Earth heat.The answer reveals one of the peculiarities of the nuclear forces.

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