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Edexcel IGCSE Physics · Spec 7.4

Half-Life, Uses & Dangers

What half-life means, and the uses and dangers of radioactivity.

Physics revision video

Half-Life, Uses & Dangers

Spec 7.4

What you need to know

  • Define half-life
  • Read a decay curve
  • Give uses and dangers of radioactivity

Active recall

Quick check

Answer each question before opening the answer.

Define half-life.

The time taken for half the radioactive nuclei in a sample to decay (or for the activity to halve).

Give one use and one danger of radioactivity.

Use — e.g. medical tracers, treating cancer, smoke detectors; danger — it can damage or kill cells and cause cancer.

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