Fortunately, the isotope has a very short​ half-life of 12 days. Estimate the percentage of the original amount of the isotope released by the explosion that remains 10 days after the explosion.

Answer 1

1/2 = e^-r(12)

ln(1/2) = -12r

-.693 =-12r

r = .0578

A= e^-0.0578(10)

= e^-.578 = 0.561 = 56.1% remains after 10 days

half life is 12 days, when 50% remains. After 10 days a little more than 50% remains