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Strontium-85, used for bone scans, has a half-life of 65 days. Part A How long will it take for the radiation level of strontium-85 to drop to half of its original level? Express your answer as an integer. IVE ΑΣΦ ? Submit Previous Answers Request Answer X Incorrect; Try Again; 3 attempts remaining Part B How long will it take for the radiation level of strontium-85 to drop to one-sixteenth of its original level? Express your answer as an integer. IVE ΑΣΦ ? Submit Request Answer Provide Feedback days days

Fluorine-18, which has a half-life of 110 min, is used in PET scans. You may want to reference (Page) Section 5.4 while completing this problem. Review | Part A If 125. mg of fluorine-18 is shipped at 10:00 A.M., how many milligrams of the radioisotope are still active after 330 min? Express the mass to three significant figures and include the appropriate units. НА ? m= Value Units Submit Request Answer Part B If 110. mg of fluorine-18 is shipped at 10:00 A.M., how many milligrams of the radioisotope are still active when the sample arrives at the radiology laboratory at 5:20 P.M.? Express the mass to three significant figures and include the appropriate units. μA ? m= Value Units Submit Request Answer

Part A A 130-mg sample of technetium-99 m is used for a diagnostic test. If technetium-99 m has a half-life of 6.0 h, how many milligrams of the technetium-99 m sample remains active 30 h after the test? Express your answer to two significant figures and include the appropriate units. i μÀ ? 4.1 Mg Submit Previous Answers Request Answer X Incorrect; Try Again; 5 attempts remaining Check that you have converted between Sl units of mass correctly.