Question 10a) The half-life of iodine-125 is 59.4 days. If the initial mass of iodine-125 is 128 ug, what mass of iodine-125 willbe remaining 297 days later? (Hint - consider this length of time in terms of the number of half-lives).b) Radioactive source A has an initial activity of 3.42 x 10* Bq and a decay constant of 4.17 × 10-9 s.Radioactive source B has an activity of 5.52 x 104 Bq and a decay constant of 8.05 x 10-9 s.i) Which of the two sources will have the highest activity after 4 years. (1 year = 3.154 x 107 s)?ii) How many years will it take source A to reach an activity of 1.00 x 10* Bq? [3.3]Question 11

a) Given, the half-life of iodine-125 is T12=59.4days the initial mass of iodine is…

a) The half-life of iodine-125 is 59.4 days. If the initial mass of iodine-125 is 128 µg, what mass of iodine-125 will be remaining 297 days later? (Hint – consider this length of time in terms of the number of half-lives). b) Radioactive source A has an initial activity of 3.42 x 10* Bq and a decay constant of 4.17 x 10-9 s*. Radioactive source B has an activity of 5.52 x 104 Bq and a decay constant of 8.05 x 10-9 s*. i) Which of the two sources will have the highest activity after 4 years. (1 year = 3.154 x 107 s)? ii) How many years will it take source A to reach an activity of 1.00 x 10* Bq? [3.3]

a) The half-life of iodine-125 is 59.4 days. If the initial mass of iodine-125 is 128 µg, what mass of iodine-125 will be remaining 297 days later? (Hint – consider this length of time in terms of the number of half-lives). b) Radioactive source A has an initial activity of 3.42 x 10* Bq and a decay constant of 4.17 x 10-9 s. Radioactive source B has an activity of 5.52 x 104 Bq and a decay constant of 8.05 x 10-9 s. i) Which of the two sources will have the highest activity after 4 years. (1 year = 3.154 x 107 s)? ii) How many years will it take source A to reach an activity of 1.00 x 10* Bq? [3.3]