et 76.9/100 12/7/201704:12 PM Periodic Table Print Calculator 19 of 30 rsity Phy
ID: 696383 • Letter: E
Question
et 76.9/100 12/7/201704:12 PM Periodic Table Print Calculator 19 of 30 rsity Physios presented by Sapling Leaming lodine-125 (251) is used to treat, among other things, brain tumors and prostate cancer. It decays by gamma decay with a half-life of 54.90 days. Patients who fly soon after receiving 1251 implants are given medical statements from the hospital verfying such treatment because their radiation could set o radiation detectors at airports If the initial decay rate (or activity) was 537 JCi, what will the rate be after 373.0 days? Number uCi How many months after the treatment will the decay rate be reduced to 13.5% of the original value? Assume months of 30 days. Number months HintExplanation / Answer
k = 0.693/t/12
k= 0.693/(54.9) = 0.0126 d-1
k = (1/t)ln(a/x)
a = living carbon ACTIVITY = 537
x = after time t activity = ?
t = time = 373 days
0.0126 = (1/373)ln(537/x)
x = after time t activity = 4.88 5
part b
k = (1/t)ln(a/x)
a = living carbon ACTIVITY = 100
x = after time t activity = 13.5
t = time = ? days
0.0126 = (1/t)ln(100/13.5)
t = time = 158.9 days
in months = 5.3
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.