## Calcuation Exercises with Amount of Radioacitve Material and Decay

1) Calculate the rate of disintegration if the following:

1. 1.0 * 1013 atoms 99mTc.
2. 1.0 * 1014 atoms 14C.
3. 1.0 gram 239Pu.
4. 1.0 gram 235U.

2) Calculate the amount of atoms of the following nuclei, based on their activity:

1. 10 MBq of 32P
2. 200 kBq of 131I

3) A source of 60Co has a rate of disintegration equal to 1.0 * 1014 Bq. What is the mass of 60Co in grams?

4) A preparation labelled 3H disintegrates with 3.0 * 105 Bq.

1. What is the rate of disintegration after 3 years?
2. How long does it take for the rate of disintegration to reach 2.0 * 105 Bq?

5) A patient is administered 4.0 * 107 Bq 99mTc in connection with a nuclear medicine examination. Calculate the amount of mass of 99mTc injected in the patient. The daughter nuclide 99Tc is radioactive, but has a very long half-life. Show that the total rate of disintegration in the patient is insignificant one week after the examination.

6) Calculate the rate of disintegration of the following:

1. 1.0 g natural Lu-metal
2. 1.0 g natural Sm-metal

7) Recently it was showed that natural Bi is radioactive. How much amount of Bi is required to give a disintegration rate of 10 Bq?

8) In nature 234U exist in equilibrium with 238U as a daughter product.

1. How much 238U has an equivalent disintegration rate as 1 g 234U?
2. Given the amounts from a) is separated as pure 238U and 234U, how many percent has the amount of 238U decreased when the amount of 234U is halved?