College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 50

A medical laboratory stock solution is prepared with an initial activity due to 24 Na of 2.5 mCi/mL, and 10.0 mL of the stock solution is diluted at t 0 = 0 to a working solution whose total volume is 250 mL. After 48 h, a 5.0-mL sample of the working solution is monitored with a counter. What is the measured activity Note: 1 mL = 1 milliliter