There are many natural occurring radioactive isotopes. Among them, Radon(222Rn), 40K and 14C are the most...

There are many natural occurring radioactive isotopes. Among them, Radon(222Rn), 40K and 14C are the most important ones.

a) Where are/ were these isotopes produced and come from? You can consult Wikipedia for this question and briefly describe where they come from

b) Consider a person of 70 Kg. 0.20% of the body mass is potassium and it is a vital nutrient. Natural potassium (mostly 39K and 41K) also contains 0.012% 40K with a half- life time of 1.3 billion years. 40K emits a β- of average energy of 58.5 keV in 89.3% of its decays and a 1.461 MeV γ-ray in 10.7% of the decays. How many of these high-energy γ-rays is generated in the person per second?

c) If you assume that all the energy from the electrons and γ-rays is absorbed in the body, what is the effective dose for the person in one year?

d) While nowadays 0.012% of all potassium is 40K, what was its share of all potassium 4.5 billion years ago, when the Earth formed?

Solutions

Expert Solution

(a)

The naturally occuring radioactive isotopes are product of stellar nucleosynthesis or cosmic ray spallation.

genius_generous answered 4 months ago

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