How much Cu-61 would remain from a 2 mg sample after 9 hours?

Answer 1

To determine how much Cu-61 remains after 9 hours, we need to know its half-life. Cu-61 has a half-life of about 3.33 hours. After 9 hours, which is approximately 2.7 half-lives, we can use the formula ( \text{Remaining mass} = \text{Initial mass} \times \left( \frac{1}{2} \right)^{n} ), where ( n ) is the number of half-lives. Thus, ( 2 , \text{mg} \times \left( \frac{1}{2} \right)^{2.7} ) yields approximately 0.31 mg of Cu-61 remaining.