Nuclear Chemistry
Ch 18, Pg 666, # 1-8
#1. What is meant by the half-life
of a radioactive nuclide?
#2. Explain how carbon-14
dating is used to determine the
age of an object.
• (Carbon-14 half life is 5.715 x 103 years =
5,715 years)
#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)
#4. Identify three practical
applications of nuclear chemistry
5. What fraction of an original
sample of a radioactive isotope
remains after three half-lives have
passed?
#6. How many half-lives of radon222 (half life 3.82 days) have
passed in 11.46 days? If 5.2 x 10-8
g of radon-222 remain in a sealed
box after 11.46 days, how much
was present in the box initially?
#7. The half-life of proactinium-234
in its ground state is 6.69 h. What
fraction of a given amount remains
after 26.76 h?
#8. The half-life of thorium-227 is
18.72 days. How many days are
required for ¾ of a given amount to
decay?