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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 quickly after its production. Because of this rapid decay, it must be used as soon as possible after it is made. Producing it close to the hospital allows for minimal loss of activity and ensures that the PET scans are effective without significant decay affecting the results.
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, which means it can only affect tissue that is very close to it. Therefore, the source of alpha radiation needs to be right next to the tumour in order to treat it effectively. In contrast, gamma radiation has a long range and high penetration, allowing it to pass through the skin and reach tumours from outside the body. This makes it suitable for delivering treatment without needing to be placed inside the body.