August 2019 NY Regents Chemistry Exam
49 Which radioisotope requires long-term storage as the method of disposal, to protect living things from radiation exposure over time?
(2) Fr-220 (3) Fe-53
Solution: We need to take a look at Table N on the Reference Table which lists half lives. The question is asking about long term storage which means we are looking for a radioisotope with a long half life. Pu-239 has a half life of 2.410 × 10^4 years. Fr-220 is 27.4 seconds, Fe-53 is 8.51 minutes , and P-32 is 14.28 days.
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