Hello, I have this question on radioactivity which Im finding hard to do:
Potassium-42 decays with a half life of 12 hours. When potassium-42 decays it emits B- particles and gamma rays. One freshly prepared source has an activity of 3.0 x10^7 Bq.
(a) To determine the dose received by a scientist working with the source the number of gamma ray photons incident on each cm² of the body has to be known.
One in every five of the decaying nuclei produces a gamma ray photon. A scientist is initially working 1.50m from the fresh shorce with no shielding. Show that at this time approximately 21 gamma ray photons per second are incident on each cm² of the scientist's body.
Thanks a lot
From john