Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
how do i do this?
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.
Is it just 131/8 until you get to 3.125?
1 Answer
- Anonymous1 decade agoFavorite Answer
no, the I-131 is the name of the radioactive iodine, the I stands for iodine and the 131 is the radioactive number.
the patient would start with 400 millicuries of the iodine in his body, after 8 days (the half life) this would have dropped to 200, another 8 days it would be 100 and so on.
day 1 = 400
day 8 = 200
day 16 = 100
day 24 = 50
day 32 = 25
day 40 = 12.5
day 48 = 6.25
day 56 = 3.125
so it would take 56 days to decay to 3.125 millicuries