Calculate the rate of disintegration of the following:
  1. 1.0 • 1013 atoms 99mTc.
  2. 1.0 • 1014 atoms 14C.
  3. 1.0 grams 239Pu.
  4. 1.0 gram 235U.


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

  1. 10 MBq of 32P
  2. 200 kBq of 131I


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


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?


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.


Calculate the rate of disintegration of the following:

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


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


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?