The half-life of ¹³¹I is 8.04 days.

(a)Convert the half-life to units of seconds. s?

(b)What is the decay constant (in s¹) for this isotope? s¹

(c)Suppose a sample of ¹³¹I has an activity of 0.370 Ci. What is this activity expressed in the SI unit of becquerels (Bq)? Bq?

(d)How many ¹³¹I nuclei are needed in the sample in part (c) to have the activity of 0.370 Ci?

? ¹³¹I nuclei

(e)Now suppose that a new sample of ¹³¹I has an activity of 6.20 mCi at a given time.How many half-lives will the sample go through in next 40.2 days? (Enter your answer for the number of half-lives to at least one decimal place.) half-livesWhat is the activity of this sample (in mCi) at the end of 40.2 days?

mCi?

( ) In go.2 days, half lives passes: 40.2 - 5.0 times. 8.04 NOW, At two, activity R = 6.20 mci So activity is given as R = aNext - Axo 6-20 mci = aNoe = 2 No NOLD after 40. 2 days = 40.2 x 24 X60 *60 = 9473280 See. The activity is given as R' = a Noeat = AND ( 9.98 *10 * 3473280 ) = AN. P (3.466 ) = 6.20 x 0.0312 mci, fromegh (1) 2No = 6.20 mci) R' = 0.193 mli