Carbon-11 Radioactively Decays by Positron Emission with a Half-Life of 20.4

question 71

Multiple Choice

Carbon-11 radioactively decays by positron emission with a half-life of 20.4 minutes. If a dosage of carbon-11 is administered to a patient for a PET scan, what percentage of carbon-11 will remain in the patient's system after 81.6 min?

• A)75.0%
• B)12.5%
• C)87.5%
• D)25.0%
• E)6.25%

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