Chapter 20.3, Problem 17R

To determine

Percentage of the radioactive nuclei that will be left after 3 half-life pass.

Answer to Problem 17R

12.5 Percentage of the radioactive nuclei will be left after 3 half-life pass.

Explanation of Solution

Introduction:

Number of Half-life of radioactive material: 3

After each half-life, the number of remaining undecayed nuclei decrease rapidly.

• After one half-life the number of remaining undecayed nuclei reduced to half (50 percent).
• And after two half-lives the number of remaining undecayed nuclei reduced to one-fourth (25 percent).
• And after 3 half-lives the number of remaining undecayed nuclei reduced to one-eighth (12.5 percent).

Conclusion:

Hence, after 3 half −life, only 12.5 percent of the radioactive nuclei that will be left.