Objective #1) TLW solve half-life problems1) The half-life of polonium-210 is 138.4 days. How many milligrams of polonium-210 remain after 415.2 days if you start with 2.0 mg of the isotope?

2) Assuming a half life of 1599 years, how many years will be needed for the decay of 15/16ths of a given amount of radium-226?

3) The half life of radon-222 is 3.824 days. After what time will one-fourth of a given amount of radon remain?

4) The half-life of cobalt-60 is 5.27 years. How many milligrams of cobalt-60 remain after 52.7 years if you start with 10.0 grams?

Objective #2) TLW determine the age of a sample given its initial and final carbon-14 content1) You are scientist working for an archeologist. While looking for mummies in Egypt your archeologist comes across the bones of what he thinks is an Egyptian slave. You run a C-14 test on the bones and find 25 nanograms of C-14 in a sample of bone that would contain 800 nanograms of C-14 if the person had died yesterday. How old are our person’s bones assuming that the half life of C-14 is about 5730 years?

Bonus: Why is our archeologist’s assumption probably wrong?

Half-life & C-14