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Edexcel IGCSE Physics · Spec 7.5

Nuclear Fission & Fusion

The difference between nuclear fission and nuclear fusion.

Physics revision video

Nuclear Fission & Fusion

Spec 7.5

What you need to know

  • Describe nuclear fission
  • Explain a chain reaction
  • Describe nuclear fusion

Active recall

Quick check

Answer each question before opening the answer.

What is nuclear fission?

A large unstable nucleus splits into smaller nuclei, releasing energy and neutrons.

What is nuclear fusion?

Two light nuclei join to form a heavier nucleus, releasing energy — as happens in stars.

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