Try It 10.90: Evaluating an Exponential Decay Model Using Half-Life
Further practice solving an exponential decay problem using half-life. Suppose the half-life of radioactive iodine is days, and we want to determine how much of a -mg sample will remain in days. Using the exponential decay formula , find the decay rate by noting that half the sample ( mg) remains after days: . Dividing by gives . Taking the natural logarithm of both sides gives , resulting in . Substitute this rate back into the formula to find the amount after days: . Evaluating this expression yields approximately mg. Therefore, about mg of the sample will be left.
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Try It 10.89: Evaluating an Exponential Decay Model Using Half-Life
Try It 10.90: Evaluating an Exponential Decay Model Using Half-Life
A medical laboratory technician needs to calculate the remaining dosage of a radioactive isotope used in diagnostic imaging. To determine the amount of the isotope remaining after several hours using the exponential decay formula , arrange the following procedural steps in the correct order.
As an environmental safety technician monitoring the breakdown of a hazardous chemical, you need to predict how much of the substance will remain in a soil sample after 5 years. You know the chemical's half-life and the initial amount in the sample. Based on the process for solving exponential decay applications, what is the required first step you must take before you can calculate the final amount?
As a laboratory technician monitoring the decay of a medical isotope, you use the exponential decay formula to predict remaining dosages for patient treatments. Match each mathematical symbol from the formula with the practical measurement it represents in your professional work.
An environmental safety technician uses the exponential decay formula to track the breakdown of chemical waste in a storage facility. In this mathematical model, the variable is formally known as the ____ constant.
In a professional laboratory setting, when using the exponential decay formula to determine the decay constant for a radioactive substance, the technician should set the remaining amount to be exactly half of the initial amount when the elapsed time is equal to the substance's half-life.
Learn After
A medical lab technician is using the exponential decay model to monitor a supply of radioactive iodine. If the isotope has a known half-life of 60 days, which equation correctly represents the first step used to solve for the decay rate ?
An environmental health and safety technician is monitoring a 50-mg sample of radioactive iodine that has a known half-life of 60 days. To determine how much of the sample will remain after 40 days, the technician uses the exponential decay model . Arrange the following steps in the correct order to solve this problem.
A hospital pharmacy technician uses the exponential decay model to manage the inventory of a radioactive isotope used in medical treatments. For a 50-mg sample with a 60-day half-life, match each mathematical component to its correct description in the technician's inventory report.
Interpreting Exponential Decay Variables
A medical laboratory technician is tracking the decay of radioactive iodine using the model . If the isotope has a known half-life of 60 days, the technician correctly identifies that after 60 days, the ratio of the amount remaining () to the initial amount () is exactly 0.5.