GCSE Physics (AQA)

346 videos | 23 hours

Contamination

Please subscribe to watch this video.

This, and all other videos, are included in our premium subscriptions.

Premium accounts get access to all videos.

Atomic structure Atoms and nuclear radiation

Contamination

2:59 Contamination and Irradiation
Spec 4.4.2.4
Previous Half-Life Calculations Next Irradiation
  • Radioactive contamination is the unwanted presence of radioactive isotopes in materials.
  • Example: Water contaminated with radioactive iodine particles.
  • Important to distinguish contamination from radiation for exams.
  • Nuclear power stations can contaminate surroundings after accidents.
  • Radioactive materials can contaminate water and soil, affecting food chains.
  • Real-life examples: Chernobyl (1986) and Fukushima (2011).
  • Nuclear power stations have extensive safety features; accidents are rare.
  • Contamination is dangerous due to unknown radiation exposure levels.
  • Example: A contaminated tree can unknowingly irradiate a person sitting under it.
  • Controlled radiation exposure is possible in medical settings.
  • Contamination risk depends on the half-life of the isotope.
  • Half-life: Time taken for radioactive activity to halve.
  • Different isotopes have different half-lives.
  • Short half-life isotopes (e.g., iodine-131) cause high irradiation quickly.
  • Long half-life isotopes (e.g., cesium-137) persist longer but irradiate less.
  • Short half-life isotopes are high risk; long half-life isotopes are low risk.
  • Exams may require describing and comparing contamination risks of different isotopes.

Please subscribe to access these revision notes.

This, and all other video notes, are included in our premium subscriptions.

Premium accounts get access to all videos and revision notes.