1. Nuclear Chemistry Ch 18, Pg 666, # 1-8

2. #1. What is meant by the half-life of a radioactive nuclide?

3. #2. Explain how carbon-14 dating is used to determine the age of an object.
(Carbon-14 half life is x 103 years = 5,715 years)

4. #3. Why is potassium-40 used to date objects older than 50,000 years old?
(half life Potassium–40 is 1.28 x 109 years)

5. #4. Identify three practical applications of nuclear chemistry

6. 5. What fraction of an original sample of a radioactive isotope remains after three half-lives have passed?

7. #6. How many half-lives of radon-222 (half life 3
#6. How many half-lives of radon-222 (half life 3.82 days) have passed in days? If 5.2 x 10-8 g of radon-222 remain in a sealed box after days, how much was present in the box initially?

8. #7. The half-life of proactinium-234 in its ground state is 6. 69 h
#7. The half-life of proactinium-234 in its ground state is 6.69 h. What fraction of a given amount remains after h?

9. #8. The half-life of thorium-227 is 18. 72 days
#8. The half-life of thorium-227 is days. How many days are required for ¾ of a given amount to decay?