PhysicsCode 5054
Fission and fusion
What this topic asks you to be able to do
- Describe fusion, in which two smaller nuclei unite to make one larger nucleus and give out energy, and recognise that fusion powers stars.
- Describe fission, the process in which a nucleus, such as uranium-235 (U-235), absorbs a neutron and then splits into daughter nuclei, giving off two or more neutrons and releasing energy
- Explain how the neutrons released in fission set up a chain reaction, and that in a nuclear reactor this reaction is kept under control, including what the coolant, moderators and control rods do