AQA GCSE PHYSICS · PAPER 1 · FOUNDATION & HIGHER
Exam Practice: Radioactive contamination and irradiation
Radioactive contamination and irradiation · Atomic structure · Lesson 7 of 10 · 12 marks · 13 minutes
|
Name |
|
Date |
|
Instructions
• Answer all the questions.
• Write your answers in the spaces provided.
• The marks for each question are shown in brackets - use this as a guide to how much to write.
• The answers are on separate pages at the back. Attempt every question before you look at them.
• Answer all questions. Use the mark allocation as a guide to how much to write.
Question 1 STATE (2 marks)
Explain the difference between radioactive contamination and irradiation.
|
|
|
|
|
|
(Total for Question 1 = 2 marks)
Question 2 EXPLAIN (3 marks)
A student says that a person who has been irradiated by a gamma source is now radioactive. Explain why the student is wrong.
|
|
|
|
|
|
|
|
(Total for Question 2 = 3 marks)
Question 3 SUGGEST (2 marks)
Give two precautions that should be taken when a teacher handles a radioactive source.
|
|
|
|
|
|
(Total for Question 3 = 2 marks)
Question 4 COMPARE (3 marks)
Compare the hazards of contamination and irradiation from an alpha source.
|
|
|
|
|
|
|
|
(Total for Question 4 = 3 marks)
Question 5 EXPLAIN (2 marks)
Scientists who study the effects of radiation on humans publish their findings. Explain why it is important that the findings are peer reviewed.
|
|
|
|
|
|
(Total for Question 5 = 2 marks)
TOTAL FOR PAPER = 12 MARKS
|
|
Answers and mark scheme
Check your answer only once you have written one.
Question 1 (2 marks)
Contamination is the unwanted presence of radioactive atoms on or in another material. Irradiation is exposing an object to radiation; the object does not become radioactive.
• Contamination: radioactive atoms present on other materials 1 mark
• Irradiation: exposure and the object does not become radioactive 1 mark
Question 2 (3 marks)
Irradiation means exposure to radiation from outside. The person has not received radioactive atoms, so they do not become radioactive.
• Irradiation is exposure 1 mark
• No radioactive atoms transferred 1 mark
• So the person is not radioactive 1 mark
Question 3 (2 marks)
Any two from: use tongs; keep the source in a lead-lined box; keep exposure time short; keep away from the body; wear gloves.
• First precaution 1 mark
• Second precaution 1 mark
Question 4 (3 marks)
Outside the body, irradiation by alpha is not hazardous because alpha is absorbed by air or skin. If contamination puts the alpha source inside the body it is very hazardous because alpha is strongly ionising and damages cells.
• Irradiation by alpha: low hazard, absorbed 1 mark
• Contamination inside the body: high hazard 1 mark
• Alpha strongly ionising 1 mark
Question 5 (2 marks)
Other scientists can check the methods and conclusions, so the results are more reliable.
• Findings checked by other scientists 1 mark
• So more reliable or valid 1 mark