Question Constellation Sign up for free AQA · GCSE · Combined Science · Higher
Detecting gamma radiation
Lanthanum-140 is a radioactive isotope.
Why is it difficult to detect gamma radiation?
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Marking points
- 1 State that gamma radiation is only weakly ionising.
- 2 Or state that most gamma radiation passes through a detector.
Full-mark answer
Gamma radiation is difficult to detect because it is only weakly ionising, so much of it passes through a detector without being detected.
Why this answer loses marks
Because gamma radiation is invisible.
Although gamma radiation cannot be seen, the credited reason is that it is weakly ionising or very penetrating.