A thyroid cancer patient is given a dosage of 131I (half-life = 8.1 d). What fraction of the dosage of 131I will still be in the patient's thyroid after 24.3 days?

A Geiger counter reading of a radioactive sample is initially 6520 counts per minute. The same sample gives a reading of 402 counts per minute 10.9 h later. What is the sample's half-life?

A Geiger counter reading of a radioactive sample is initially 7420 counts per minute. The same sample gives a reading of 422 counts per minute 11.0 h later. What is the sample's half-life?

A 75 kg patient swallows a 33 μCi beta emitter whose half-life is 5.0 days and whose RBE is 1.6. The beta particles are emitted with an average energy of 0.35 MeV, 90% of which is absorbed by the body. You are a health care worker needing to find the patient's dose equivalent after one week. These series of steps will help you find that dose equivalent. In all questions, assume the radioactive nuclei are distributed throughout the patient's body and are not being excreted. Part A How many radioactive nuclei did the patient swallow? Express your answer using three significant figures. ▸ View Available Hint(s) No= ΜΕ ΑΣΦ Submit ?