Problem 28
If \(160 \mathrm{mg}\) of technetium-99 is administered for a medical diagnosis, how much of the nuclide remains after 24 hours? \(\left(t_{1 / 2}=6\right.\) hours \()\).
Problem 29
Small beads of iridium- 192 are sealed in a plastic tube and inserted through a needle into breast tumors. If an Ir-192 sample has an initial activity of \(560 \mathrm{dpm}\), how much time is required for the activity to drop to \(35 \mathrm{dpm} ?\) \(\left(t_{1 / 2}=74\right.\) days \()\).
Problem 30
If an iron-59 sample has an initial activity of \(200 \mathrm{dpm}\), how much time is required for the activity to drop to \(25 \mathrm{dpm} ?\left(t_{1 / 2}=45\right.\) days \()\).
Problem 31
The initial radioactivity of a cobalt- 60 sample was 1200 dpm and after 21.2 years the activity dropped to \(75 \mathrm{dpm}\). What is the half-life of the radionuclide?
Problem 32
If \(2400 \mu g\) of hydrogen- 3 decay to \(600 \mu g\) after 24.8 years, what is the half-life of this radionuclide that is used as a chemical tracer?
Problem 33
What radionuclide technique can be used to estimate the age of fossils up to 50,000 years old?
Problem 34
What radionuclide technique can be used to estimate the age of geological events up to a few billion years?
Problem 35
What radionuclide can be used to sterilize male insects and control pests?
Problem 36
What radionuclide can be used to irradiate food and destroy microorganisms?
Problem 38
What \(\gamma\) -emitting radionuclide can be used to diagnose and locate inactive lung tissue in the respiratory system?
