A radioactive isotope of potassium (K) has a half-life of 20 minutes. If a 40.0 gram sample of this isotope is allowed to decay for 80 minutes, how many grams of the radioactive isotope will remain?
2 Answers
Mar 5, 2018
The mass is
Explanation:
The equation for the radioactive decay is
where
The half life of
The initial mass is
The time is
Therefore,
The quantity remaining is
Mar 5, 2018
As half life is 20 minutes, the half of the material will decay in each slot of 20 minutes,therefore after 80 minutes one will have only 2.5 grams of the sample left out of 40 grams.