Radioactivity test with answers for GCSE physics (free PDF download)

Question 1 Stopping radiation (2 marks)

First, state which type of radiation a sheet of paper stops, and which type needs thick lead to reduce it.

Question 2 Alpha decay equation (3 marks)

For example, uranium-234 has the atomic number 92 and decays by emitting an alpha particle. Also, thorium has the atomic number 90.

Then, give the mass number and atomic number of the new nucleus, and name it.

Question 3 Half-life calculation (3 marks)

For example, a sample has an activity of 2400 Bq and a half-life of 12 days.

Then, calculate its activity after 36 days.

Question 4 Reading the decay graph (3 marks)

First, the graph shows the activity of a radioactive sample.

1. First, use the graph to find the half-life. (1 mark)
2. Then, state the activity after 15 minutes. (1 mark)
3. Finally, calculate the time for the activity to fall to 20 kBq. (1 mark)

Question 5 Irradiation and contamination (3 marks)

Also, explain the difference between irradiation and contamination, and give one precaution that reduces the risk of contamination.

Question 6 Fission and fusion (2 marks)

Next, state which process, fission or fusion, nuclear power stations use and which one takes place in the Sun.

Question 7 Choosing a tracer (2 marks)

For example, a doctor needs a radioactive tracer to inject into a patient. Then, explain why an isotope with a half-life of 6 hours is better than one with a half-life of 6 years.

Question 8 Beta particles (2 marks)

Finally, state what a beta particle is and describe how the nucleus produces it.