A radioactive source emits alpha, beta and gamma radiation - AQA - GCSE Physics Combined Science - Question 2 - 2021 - Paper 1

When an atom is ionised by an alpha particle, it becomes a positive ion and it also loses an electron.

A spark detector cannot detect beta radiation because beta radiation is only weakly ionising, meaning it does not efficiently ionise the air to create a spark.

1. Move the radiation detector very close to the radioactive source.

2. Record the initial count rate on the radiation detector.

3. Position a sheet of paper between the radioactive source and the radiation detector.

4. Record the new count rate; alpha radiation will not penetrate through the paper.

5. If the count rate with the paper is significantly less compared to the initial count rate, then alpha radiation is confirmed.

6. Remove the paper and position an aluminium sheet between the source and the detector.

7. Record the count rate again. Beta (and gamma) radiation will penetrate through the aluminium.

8. If the count rate has not significantly dropped compared to when the paper was used, then beta radiation is present.

9. Additionally, if radiation penetrates through the aluminium then gamma radiation is detected as well.

10. Repeat the experiment to ensure consistent results and minimize the effect of random variations.