Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Radioactivity and Particles
123 practice questions
Topics covered
Practice questions
51–59 of 59 · Normal
Question 51
5 marks · Normal
Answer and see the solution →The diagrams below show two types of nuclear reaction used to generate energy on Earth and in stars.
(a)[3 marks]Describe how energy is released in a nuclear fission reactor. Include the roles of the moderator and control rods in your answer.
(b)[2 marks]Explain why nuclear fusion reactions occur readily in stars but are harder to achieve on Earth.
Question 52
4 marks · Normal
Answer and see the solution →The nuclear reaction below shows a fusion reaction that occurs in stars:
(a)[2 marks]Explain what happens to the total mass of the products compared to the reactants in this reaction, and state what happens to the 'missing' mass.
(b)[2 marks]Describe one reason why nuclear fusion does not produce long-lived radioactive waste, unlike nuclear fission reactors.
Question 53
5 marks · Normal
Answer and see the solution →A nuclear power station can use either a fission reactor or, in the future, a fusion reactor.
(a)[3 marks]State two similarities and two differences between nuclear fission and nuclear fusion as sources of energy.
(b)[2 marks]Suggest one reason why fusion reactors could be more desirable than fission reactors for providing energy on Earth.
Question 54
5 marks · Normal
Answer and see the solution →A hospital uses a radioactive tracer to detect problems in a patient's kidneys. The tracer contains an isotope that decays by beta emission. The activity of a sample is measured as 3.0 kBq.
(a)[2 marks]State what is meant by the unit becquerel (Bq) and convert the sample's activity to becquerels.
(b)[2 marks]Explain why a beta emitter is often chosen for medical tracers rather than an alpha emitter.
(c)[1 mark]Describe one safety precaution that should be taken when using radioactive tracers in medicine.
Question 55
4 marks · Normal
Answer and see the solution →Read these two statements about radioactivity: Statement 1: The activity of a radioactive sample is measured in becquerels (Bq). Statement 2: Gamma radiation is more penetrating than alpha radiation.
(a)[1 mark]Explain what is meant by the unit 'becquerel' (Bq).
(b)[1 mark]Why is gamma radiation more dangerous than alpha radiation outside the body? Give a reason.
(c)[1 mark]A sample has an activity of 500 Bq. How many decays does this represent per second?
(d)[1 mark]State one common way to detect ionising radiation in a laboratory.
Question 56
4 marks · Normal
Answer and see the solution →A sample containing a radioactive isotope has an initial activity of 200 Bq. The half-life of the isotope is found to be 15 minutes.
(a)[2 marks]Calculate the activity of the sample after 30 minutes.
(b)[1 mark]State the unit for activity.
(c)[1 mark]Explain what is meant by the 'half-life' of a radioactive isotope.
Question 57
5 marks · Normal
Answer and see the solution →A hospital uses a radioactive isotope that emits gamma radiation to sterilise medical equipment and measure the thickness of plastic film. The table shows typical penetrating and ionising properties of the three main types of radiation.
Penetrating and Ionising Properties Radiation Penetrating Power Ionising Power Alpha Low (stopped by paper) High Beta Medium (stopped by aluminium) Medium Gamma Very high (stopped by thick lead) Low (a)[2 marks]Explain, using information from the table, why gamma radiation is suitable for both sterilising equipment and measuring the thickness of plastic film.
(b)[2 marks]The activity of the radioactive source is measured in a laboratory. A scientist records a value of 5000 Bq at the start. State what the unit becquerel measures and convert the recorded activity to kBq.
(c)[1 mark]Describe one safety precaution that workers should follow when handling radioactive sources.
Question 58
5 marks · Normal
Answer and see the solution →A student investigates the penetration of different types of radiation in a laboratory experiment and learns how radioactive substances can be detected.
(a)[2 marks]Name one instrument that can detect ionising radiation and briefly describe how it works.
(b)[2 marks]The student places a piece of aluminium between a radioactive source and a Geiger-Müller tube. The count rate drops to background level. Explain what this tells you about the type of radiation being emitted and why.
(c)[1 mark]State one unit you would use to record the activity in this investigation.
Question 59
5 marks · Normal
Answer and see the solution →A scientist uses a Geiger-Muller tube to investigate a radioactive isotope in the laboratory. The isotope decays by emitting beta particles. The scientist also uses a stopwatch to record results.
(a)[1 mark]State the unit used to measure the activity of the radioactive isotope.
(b)[2 marks]Explain how the Geiger-Muller tube detects ionising radiation.
(c)[2 marks]Describe what happens to the atomic number and mass number of the isotope after each beta decay.