GCSE Questions: Radioactivity
(a) Alpha particles (α), beta particles (β) and gamma rays (γ) are types of nuclear radiation.
(i) Which of the three types of radiation is the most strongly ionising?
(ii) What effect does nuclear radiation have on living cells?
(b) The diagrams show a G-M tube and counter used to measure the radiation emitted from a source. Both diagrams show the reading on the counter one minute after it was switched on.
Explain why the counter readings show that the source is giving out only gamma radiation.
(c) The box gives information about the radioactive isotope technetium-99. What is meant by the term half-life?
(d) To study the blood flow in a patient's lungs, a doctor injects a small quantity of a technetium-99 compound into the patient. The radiation emitted by the technetium-99 atoms is detected outside the patient's body. Explain why a doctor would not use a radioactive isotope with a very short half-life, such as 2 seconds, as a medical tracer.
(Total 7 marks)