Nuclear physics: past paper questions
Real questions on nuclear physics
The newest 20 of 207 written questions, plus 48 multiple-choice. Open one to see it on the real paper.
- 9702/21 · October/November 2025 · Q6b(i)[2]
Complete the equation to represent the radioactive decay of tritium. 3 1 H He + β + 0 X (i)
See it on the paper → - 9702/21 · October/November 2025 · Q6b(ii)[1]
State the name of particle X.
See it on the paper → - 9702/23 · October/November 2025 · Q6b(i)[2]
Complete the equation to represent the radioactive decay of tritium. 3 1 H He + β + 0 X (i)
See it on the paper → - 9702/23 · October/November 2025 · Q6b(ii)[1]
State the name of particle X.
See it on the paper → - 9702/23 · October/November 2025 · Q6c[2]
Determine the quark composition of a tritium nucleus.
See it on the paper → - 9702/42 · October/November 2025 · Q9a[2]
State what is meant by the mass defect of a nucleus.
See it on the paper → - 9702/42 · October/November 2025 · Q9b[4]
Table 9.1 nuclide nuclide mass / u 2 1 H 2.013 553 4 2 He 4.001 505 Calculate the energy released in the formation of 1.00 mol of helium-4. energy = J Table 9.1 shows the masses of the nuclides involved in this reaction. 4 2 He. 2 2 1 H + 1 H (b) The nuclear fusion reaction for the formation of helium-4 from deuterium...
See it on the paper → - 9702/42 · May/June 2025 · Q10a[1]
Radioactive decay is a spontaneous process. State the meaning, in this context, of the term spontaneous.
See it on the paper → - 9702/42 · May/June 2025 · Q10b(i)[3]
Complete Table 10.1 to give expressions, in terms of either or both of A and T, for the quantities indicated for each of the samples. Table 10.1 sample half-life decay constant initial activity X 4A Y A initial number of nuclei
See it on the paper → - 9702/42 · May/June 2025 · Q10b(ii)[3]
Determine, in terms of T, the time at which the two samples will have equal activities. time = T
See it on the paper → - 9702/42 · May/June 2025 · Q10c[2]
A radiation detector is placed near to one of the samples in (b). Explain why the count rate measured by the detector is less than the activity of the sample.
See it on the paper → - 9702/43 · May/June 2025 · Q9a[1]
Define activity of a radioactive sample.
See it on the paper → - 9702/43 · May/June 2025 · Q9b[3]
Explain why the variation with time of the activity of a radioactive sample is exponential in nature.
See it on the paper → - 9702/43 · May/June 2025 · Q9c(i)[2]
Determine the decay constant, in min –1 , of the radioactive isotope. decay constant = min –1
See it on the paper → - 9702/43 · May/June 2025 · Q9c(ii)[1]
Use your answer in (c)(i) to determine the half-life, in min, of the radioactive isotope. half-life = min
See it on the paper → - 9702/43 · May/June 2025 · Q9c(iii)[3]
On Fig. 9.1, sketch the variation of the activity A of the sample with t for values of t between t = 0 and t = 24 min. 200 150 A / Bq 100 50 0 4 0 8 12 16 t / min 20 24
See it on the paper → - 9702/22 · February/March 2025 · Q7a[1]
Complete the equation for this decay. 88 Q 222 4 R + 2 α
See it on the paper → - 9702/22 · February/March 2025 · Q7b[3]
By considering momentum, calculate the speed of nucleus R after the decay. speed = m s –1
See it on the paper → - 9702/22 · February/March 2025 · Q7c[3]
State three quantities that are conserved during the decay.
See it on the paper → - 9702/42 · February/March 2025 · Q9a(i)[1]
random
See it on the paper →
What examiners said
The majority of candidates gave the two correct values. The most common incorrect value of the nucleon number of Q was 218 and the most common incorrect value of the proton number of R was 90.
— Examiner report, February/March 2025, 9702/22 Q7(a) (Cambridge)
The stronger candidates were able to apply the conservation of momentum to the correct nuclei in this decay. A common error was to use the proton number instead of the mass number for both particles. Many weaker candidates attempted to include particle Q and assigned it a non-zero speed, meaning they could make little progress. A significant number of the weakest candidates seemed unaware of how t...
— Examiner report, February/March 2025, 9702/22 Q7(b) (Cambridge)
Very few candidates managed to give three quantities that are conserved. ‘Momentum’ and ‘charge’ were the most common correct answers. ‘Mass’ and ‘energy’ were the most common incorrect answers. A small number of candidates scored a mark for mass-energy. Very few candidates gave ‘nucleon number’ or ‘proton number’ despite having (usually correctly) applied the conservation of both quantities in 7(...
— Examiner report, February/March 2025, 9702/22 Q7(c) (Cambridge)
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