Answer to Question #347539 in Physics for Loie

Question

A radioactive substance with a half-life of 3.0 days has an initial activity of 0.24Ci. What is its activity after 6.0 days?

Answer 1

$$A=A_0*2^{-t/t_{1/2}}$$

$$A=0.24*2^{-6.0/3.0}=0.06\:\rm Ci$$