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Question
Thorium 90Th232 is disintegrated into lead 82Pb200. Find the number of α and β particles emitted in disintegration.
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Solution
When an α-particle is emitted by an atom, its atomic number decreases by 2 and mass number decreases by 4.
When 90Th232 disintegrates to 82Pb200, 8 α particles are emitted.
When a β-particle is radiated, the atomic number increases by 1 and mass number does not change.
When 90Th232 disintegrates to 82Pb200, 8 β particles are emitted.
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