a certain radioactive isotope has leaked into small stream O

a certain radioactive isotope has leaked into small stream. One hundred days after the leak, 6% of the orginal amount of the substance remained. determine the half life of this

Solution

Using expenetial decay equation for leak:

N = Noe^(-kt)

0.06No = Noe^(-k*100)

0.06 = e^(-100k)

ln(0.06) = -k*100

2.81 = 100k

k = 0.0281

Half Life = 0.693/k = 24.66 days