As a health physicist, you are being consulted about a spill in a radiochemistry lab. The isotope spilled was 400 µCi of barium-131, which has a half-life of 12 days. (a) What mass of this radioisotope was spilled? (b) Your recommendation is to clear the lab until the radiation level has fallen 1 µCi. How long will the lab have to be closed?

You have a sample of unknown medication that is radioactive. You believe you should be able to identify the medication if you can deduce its half-life. You measure its initial activity as 2.30e+06 Bq. 10.4 hours later you measure its activity as 8.10e+05 Bq. a) What is the half-life of this unknown sample? hour b) How many nuclides are present when the activity is 8.10e+05 Bq?

iodine 131 has a half life of 8.04 days if you start with a radioactivr I 131 sample having an activity equal to 40 microci after how long is the activity going to be 4cmicroci

Archeologist extracted 179 gm of carbon from an animal bone from an archeological site. The carbon shows an activity of 15 decays/s. (Half-life of 146C = 5730 years, 1 year = 3.156 x 107 seconds, Avogadro's number = 6.02 x 1023 atoms/mol) (A) Total number of atoms in this carbon sample =        . (B) Decay constant of 146C, λ =           . (C) Number of 146C atoms in this sample =          . (D) Activity of 146C at time (t = 0) =            . (E) Age of the animal =