Question

A Typical Human Body Contains About 3.0 Grams Of Potassium Per Kilogram Of Body Mass. 1. ... 1. How much Potassium-40 is present in a person with a mass of 80 kg? 2. If ... of Potassium-40 results in 1.10 MeV of energy absorbed, determine the effective dose (in Sieverts) per year due to Potassium-40 in an 80- kg body.

Answer 1

Given

Per Kg of body mass, there is 3 gram of potassium

And abundance of three isotopes are as follows

Potassium-39, Potassium-40, and Potassium-41. Have abundances respectively as 93.26%, 0.012% and 6.728%.

1) A body weighing 80 Kg will have 240 grams of potassium. And the amount of Potassium-40 will be 0.012% of 240 gram

= 240*0.012/100 = 0.0288 gram.

2) Dose in (Gy) = (energy absorbed)/(mass of the body) = ( 1.1*106*1.6*10-19)/(80) = 22*10-10 J/kg

Dose (in siverts) = RBE*Dose(in Gy) = 1.2*22*10-10 = 26.4*10-10