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9(c)3 marks

Radioactive isotope X decays to isotope Y; a sample contains only nuclei of X at time t = 0, the number of nuclei of X then being 4.0 × 10²² . The mass of radioactive isotope X in the sample is 7.3 × 10⁻⁴ kg at time t = 0.

Determine the nucleon number of isotope X.

9702/41/M/J/24Cambridge International AS & A Level Physics 9702 · May/June 2024 · Paper 4 variant 1 · Question 9(c)

Fig. 9.1 — see the question text for what it shows

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Suggested time: 5 min