Radioactive reactions follow principles dealing with Chemical Kinetics.
Concept #1: Understanding Positron Emission.
Radioactive decay follows a 1st order mechanism and so has a similar integrated rate law equation from Chemical Kinetics.
Example #1: A sample of radon-222 has an initial α particle activity (A0) of 8.5 x104 dps (disintegrations per second). After 7.3 days, its activity (A) is 3.7 x 104 dps. What is the half-life of radon-222?
Example #2: Gallium citrate, containing the radioactive isotope gallium – 67, is used medically as a tumor seeking agent. It has a half – life of 78.2 hours. How long will it take for a sample of gallium citrate to decay to 20.0% of its original activity?
Example #3: What percentage of carbon – 14 ( t1/2 = 5715 years) remains in a sample estimated to be 16,230 years old?