Question

The half life of a radioactive isotope is 10 minutes. The number of radioactive nuclei at given time is 10^8

Answer 1

After 3 half-lives there will be 12.5% of the original isotope, and 87.5% of the decay product. After 4 half-lives there will be 6.25% of the original isotope, and 93.75% of the decay product. After 5 half-lives there will be 3.125% of the original isotope, and 96.875% of the decay product.