Nuclear Fusion P
Overview
The Sun is lighter now than it was when you started reading this sentence. Not because anything fell off it, and not because it burned away: because a few million tonnes of its matter stopped being matter altogether and left as light. That exchange has been running without a pause for four and a half billion years, it is the reason the sky is bright, and the entire mechanism is four statements long.
This lesson takes those four statements apart. You will find out what has to be true of a pair of nuclei before they can join at all, why two objects carrying the same sign of charge take such extraordinary conditions to bring together, and where the released energy actually comes from, which is the one part of this topic that genuinely has no everyday parallel. You will also learn exactly what a 9203 paper can ask you to work out here and what it cannot, because the boundary is sharper on this topic than on almost any other and candidates lose marks on both sides of it.
Objectives
- Nuclear fusion is the joining of two light nuclei to form a heavier nucleus.
- In this process some of the mass of the smaller nuclei is converted into energy.
- The force of repulsion between the two positive nuclei must be overcome for them to get close and fuse and this happens at very high temperatures and pressures.
- Nuclear fusion is the process by which energy is released in stars.
Mind map
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Nuclear Fusion P. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- What is nuclear fusion? A. The splitting of a large nucleus into two smaller nuclei B. The joining of two light nuclei to form a heavier nucleus C. The emission of an alpha particle from an unstable nucleus D. The removal of electrons from an atom to form an ion Answer: B
- Where does nuclear fusion take place? A. In a Geiger counter B. In a nuclear reactor C. In a star D. In a transformer Answer: C
- Why must very high temperatures be reached before nuclear fusion can occur? A. So that the nuclei have enough energy to overcome the repulsion between them B. So that the electrons can be attracted into the nucleus C. So that the nuclei become unstable and split D. So that neutrons are released to start a chain reaction Answer: A
- In a fusion reaction, the total mass of the nuclei formed is slightly less than the total mass of the nuclei that reacted. What has happened to the missing mass? A. It has been emitted as a neutron B. It has been converted into energy C. It has been left behind as radioactive waste D. It has been shared between the surrounding electrons Answer: B
- Which statement about nuclear fusion and nuclear fission is correct? A. Fusion joins nuclei and fission splits a nucleus; both release energy B. Fusion splits a nucleus and fission joins nuclei; both release energy C. Fusion releases energy and fission absorbs energy D. Both processes join nuclei, but only fusion releases energy Answer: A
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Work through these questions in the app
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