Question 266691

Natural potassium contains K-40, which has a half-life of 1.277 x 109 years.

a.What mass of K-40 in a person would have a decay rate of 4140 Bq?

b.What is the fraction of K-40 in natural potassium, given that the person has 140 g in his body? (These numbers are typical for a 70-kg adult.)