The energy of the three radiations is absorbed by the material through which the radiation passes. The amount of energy which is absorbed depends on the type of radiation and the type of the absorbing material.
The question below will test your knowledge of the absorption of alpha, beta and gamma radiation.
The diagram shows the readings obtained when a Geiger Muller tube is placed near a piece of radioactive rock. The readings obtained when the rock is wrapped in a sheet of paper and in a thick layer of aluminium foil are also shown.
The radiation emitted by the radioactive rock is:
You should have noticed that some of the radiation is absorbed by the sheet of paper. This suggests that some of the radiation from the rock is alpha radiation.
Then you should have noticed that when the rock is wrapped in a thick layer of aluminium foil the count rate of the radiation detected is reduced. This suggests that some of the radiation from the rock is beta radiation.
You should also have noticed that even when the rock is wrapped in the thick layer of aluminium foil some radiation is still being detected. Since beta radiation is absorbed by a few mm of aluminium, this suggests that gamma radiation is also coming from the rock.
Well done if you selected E as your answer. If you selected D you made a good attempt, but you did not use fully all of the information that was given to you in the diagram. If you selected A, B or C then you should go back and revise this topic again.