When an atom of potassium 40 decays into argon 40, the argon atom produced is trapped by the crystalline structure of the lava. Along with uranium and thorium, potassium contributes to the natural radioactivity of rocks and hence to the Earth heat.

Is potassium-40 radioactive or stable?

Potassium-40 is a naturally occurring radioactive isotope of potassium. (An isotope is a different form of an element that has the same number of protons in the nucleus but a different number of neutrons.) Two stable (nonradioactive) isotopes of potassium exist, potassium-39 and potassium-41.

Is K40 a radioactive isotope?

K40 is radioactive with a half-life of 1.277 x 109 years. K40 decays in the following way: K40 has an 89.28% chance to undergo beta decay to the ground state of Ca40, and a 10.72% chance to undergo electron capture to Ar40.

Where is k40 found?

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.

Is anyone from Chernobyl still alive?

Perhaps 10 percent of them are still alive today. Thirty-one people died as a direct result of the accident, according the official Soviet death toll.

What makes a banana radioactive?

Bananas are slightly radioactive because they contain potassium and potassium decays. You would have to eat a LOT of bananas just to compete with the natural potassium dose of your body. Other radioactive potassium-rich foods include spinach, white beans, apricots, salmon, avocados, mushrooms, and yogurt.