Q. The half life period of 84Po218 is 3 minutes. What percentage of the sample has decayed in 15 minutes?
1 HLP = 3 minutes
In 15 minutes, there are 3 HLPs
The remaining part of radioactive substance = (½)3
Therefore The percentage of remaining part of radioactive substance = (½)3 X 100%
= 12.5 %
Decayed percentage = 100 - 12.5 = 87.5 %