Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
Nuclear reactions as a source of energy
19 practice questions
Practice questions
11–19 of 19
Question 11
1 mark · Normal
Answer and check →Which of the following is NOT a product of uranium-235 fission?
- A.barium-144
- B.krypton-89
- C.proton
- D.neutron
Question 12
2 marks · Normal
Answer and see the solution →Name and briefly describe the function of two components used to control the rate of fission reactions in a nuclear reactor.
Question 13
3 marks · Normal
Answer and see the solution →Explain why shielding is needed around a nuclear reactor. Give two reasons.
Question 14
3 marks · Normal
Answer and see the solution →Describe how a chain reaction is produced in a nuclear reactor using uranium-235.
Question 15
4 marks · Normal
Answer and see the solution →Consider the following nuclear fission equation for uranium-235:
Answer the following questions about it.
(a)[1 mark]How many neutrons are produced in this fission reaction?
(b)[3 marks]Verify that both mass and atomic numbers are conserved on both sides of the equation.
Question 16
3 marks · Normal
Answer and see the solution →Some of the energy released in nuclear fission leaves the reactor as electromagnetic radiation. Explain why most of the energy from fission comes from the kinetic energy of the products rather than from electromagnetic radiation.
Question 17
5 marks · Hard
Answer and see the solution →A nuclear power plant uses uranium-235 as its fuel. The process of fission for a single uranium-235 nucleus is represented by the equation:
(a)[3 marks]Explain, step by step, how the products of this reaction lead to the release of energy. In your answer, refer to how the energy is distributed between the different products.
(b)[2 marks]Describe what happens to the neutrons that are produced in this reaction in a working nuclear reactor. Include the roles of the moderator and control rods in your answer.
Question 18
4 marks · Hard
Answer and see the solution →Nuclear fusion is the process that powers stars, while nuclear fission is used in reactor power plants on Earth.
Compare and explain, in detail, why it is much more difficult to start and sustain nuclear fusion reactions on Earth than nuclear fission. Your answer should refer to the forces involved and the conditions needed.
Question 19
5 marks · Hard
Answer and see the solution →A sample of uranium-235 is kept in a laboratory. It is observed that a chain reaction does not start when only a small amount is present.
(a)[2 marks]Explain why a chain reaction cannot be set up in a very small mass of uranium-235, using the concept of critical mass.
(b)[3 marks]Calculate and explain what happens to most of the neutrons that are produced during fission in a sub-critical sample. Suggest two different ways these neutrons are prevented from causing further fission.