A sealed gamma source is removed from beside a worker. No radioactive material has escaped. Which statement describes the effect of removing the source?
Exposure continues because absorbed gamma rays are stored in the worker.
Exposure continues because the worker now contains the radioactive source.
Exposure from that source stops, and existing cell damage disappears.
Exposure from that source stops, but existing cell damage may remain.
97 exam-style questions on Edexcel GCSE Physics 6.5 Uses and dangers of radioactivity, covering 6.5.1 Uses of radioactivity, 6.5.2 Dangers of ionising radiation and precautions, 6.5.3 Half-life and radiation dangers, 6.5.4 Safety precautions for radiation exposure, and 6.5.5 Contamination and irradiation. Each one has a worked solution and a mark scheme showing where the marks go.