Asked by Liz

Radioactive iodine treatment is so successful at treating hyperthyroidism that it has virtually replaced thyroid surgery. To the nearest full day, determine how long it will take for 400 millicuries of I-131, which has a half-life of 8 days, to decay to 3.125 millicuries.

56 days,
7 days,
128 days,
or
8 days

which one is it?

Answers

Answered by drwls
3.125/400 = (1/2)^(t/8)
(if t is in days)
7.8125*10^-3 = (1/2)^(t/8)

t/8 = Log(7.8125*19^-3)/Log(1/2)
= 7
t = 56 days
Answered by Liz
thank you so much!!
There are no AI answers yet. The ability to request AI answers is coming soon!

Related Questions