Thorium is a naturally occurring radioactive metal found in trace amounts in the Earth's crust.
What is the general term for the low-level ionizing radiation that is constantly present in the natural environment?
A background radiation B thermonuclear fusion C induced fission D cosmic shielding
There are two potential hazards involving alpha radiation:
Explain why inhaling the radioactive dust presents a severe health hazard, whereas the sealed solid source poses almost no risk to external body tissues.
Thorium-232 and Thorium-228 are both isotopes of thorium.
A nucleus of Thorium-232 has 90 protons. How many protons are there in a nucleus of Thorium-228?
A 90 B less than 90 C more than 90 D none
A nucleus of Thorium-232 has 142 neutrons. How many neutrons are there in a nucleus of Thorium-228?
A 90 B 138 C 142 D 228
The graph below shows how the activity of a sample of a thorium decay product changes over a period of time.
Write down the standard SI unit of activity that should complete the label on the vertical axis.
Explain what is meant by the term half-life of a radioactive isotope.
Use the graph to determine a value for the half-life of this isotope.
