Question 1
A 100-mg technetium-99m sample is used in a medical study. How much of the Technetium-99m sample remains after 24 hours? The half-life of Tc-99m is 6 hours.
Question 2
Krypton-81m is used for lung ventilation studies. Its half-life is 13 seconds. How long does it take the activity of this isotope to reach one-quarter of its original value?