Question

The half life period of a radioactive element is 27.96 days. Calculate the time taken by a given sample to reduce to 1/8th of its initial activity

Answer 1

You need k.
k = 0.693/t<sub>1/2</su>

Then ln(No/N) = kt
Set No = 100
Set N = 100*1/8 =?
k from above.
Solve for t in days.