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The diagram shows what happens when a positron and electron collide - Edexcel - GCSE Physics - Question 5 - 2016 - Paper 1
Question 5
The diagram shows what happens when a positron and electron collide. a) (i) What is the name given to this interaction between a positron and an electron? Put a cro... show full transcript
Worked Solution & Example Answer:The diagram shows what happens when a positron and electron collide - Edexcel - GCSE Physics - Question 5 - 2016 - Paper 1
Step 1
What is the name given to this interaction between a positron and an electron?
Answer
The interaction between a positron and an electron is known as annihilation. During this process, the positron and electron collide, leading to the conversion of their mass into energy in the form of two gamma rays that are emitted in opposite directions.
Step 2
What does a PET scanner use to produce positrons?
Answer
A PET scanner utilizes radioactive isotopes as a source for positrons. Specifically, isotopes like fluorine-18 are used, as they are beta-plus emitters that produce positrons when they decay. These isotopes are often attached to glucose to track metabolic activity in the body.