Question

A drug tagged with 99U (half-life = 6.05 hr) is prepared for a patient. If the original activity of the sample was 1.18E+4 Bq, what is its activity after it has sat on the shelf for 2.44 hr? Give answer in decays/s. Do not enter units.

Answer 1

Here ,

half life , t0.5 = 6.05 hour

intial activity , Ao = 1.18 *10^4 Bq

Now, after 2.44 hours

let the activity is A

A = Ao * (0.5)^(t/t0.5)

A = 1.18 *10^4 * 0.5^(2.44/6.05)

A = 8922.3 dacays/s

the activity after 2.44 hour is 8922.3 dacays/s