A wooden artifact from an archeological dig contains 60 percent of the carbon-14 that is present in living trees. To the nearest year, how long ago was the wood for the artifact cut from the tree? Note that the half-life of carbon-14 is 5 730 years.
A doctor injected a patient with 13 milligrams of radioactive dye that decays exponentially. After 12 minutes, there were 4.75 milligrams of dye remaining in the patient’s system. Which of the following is an appropriate model for this situation?
At the start of an experiment, a scientist has a sample which contains 250 milligrams of a radioactive isotope. The radioactive isotope decays exponentially, so that after 250 minutes there are only 32.0 milligrams of the isotope left.
Write the mass of isotope in milligrams, , as a function of the time in minutes, , since the experiment started. Give your answer in the form , rounding and to three significant figures.
Find the half-life of the isotope, giving your answer to the nearest minute.
A scientist begins with 100 mg of a radioactive substance that decays exponentially. After 35 hours, 50 mg of the substance remains. How many milligrams will remain after 54 hours? If necessary, round your answer to 2 decimal places.