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Energy from the nuclei of atoms can be used in medical diagnosis and treatment - Edexcel - GCSE Physics - Question 8 - 2019 - Paper 1
Question 8
Energy from the nuclei of atoms can be used in medical diagnosis and treatment. (i) Fluorine-18 is a radioactive isotope used in PET scanners for medical diagnosis.... show full transcript
Worked Solution & Example Answer:Energy from the nuclei of atoms can be used in medical diagnosis and treatment - Edexcel - GCSE Physics - Question 8 - 2019 - Paper 1
Step 1
Explain why fluorine-18 must be produced close to the hospital where it is used.
Answer
Fluorine-18 has a short half-life, which means it decays rapidly. Therefore, it must be used as soon as possible after production to ensure that sufficient quantities are available for diagnostic purposes. Producing it close to the hospital minimizes the time between production and use, ensuring its effectiveness in PET scans.
Step 2
Explain why the source of alpha radiation is usually inside the body but the source of gamma radiation can be outside the body.
Answer
Alpha radiation has a short range and low penetration power, which means it cannot travel far and is easily absorbed by tissues. Therefore, for effective treatment of tumours, the source of alpha radiation needs to be placed close to or inside the body to target the tumour directly.
In contrast, gamma radiation has a long range and high penetration capability, allowing it to pass through tissues and even skin. As a result, sources of gamma radiation can be positioned outside the body, effectively reaching internal tumours without needing to be inserted.