Solve the each problem given below:
Problem I: A radioactive isotope has an activity of 8.44 mCi. After 4.00 hours the activity is 5.40 mCi. What is the half-life of the isotope?
Problem II: What is the activity after an additional 4.00 hours in mCi units?
Please explain the equations and steps are used to get the answer. Thanks!