The newest 20 of 193 written questions. Open one to see it on the real paper.
State the name of particle X.
See it on the paper →State the type of radioactive decay experienced by P.
See it on the paper →State the type of radioactive decay experienced by Q.
See it on the paper →State what is meant by radioactive decay.
See it on the paper →Calculate the decay constant of X. Give a unit with your answer. decay constant
See it on the paper →Calculate the activity of the sample at t = 20.0 minutes. activity =
See it on the paper →On Figure 9.1, sketch the variation of the activity A of the sample with t between t = 0 and t = 20.0 minutes. Al10"4Bq 0 5 10 15 20 t/min Figure 9.1
See it on the paper →Ascientist uses a radiation detector to determine the measured count rate of radiation emitted by the sample in 9(b). Explain why the measured count rate at any given time is less than the activity of the sample.
See it on the paper →Complete the equation to represent the radioactive decay of tritium. 3 1 H He + β + 0 X (i)
See it on the paper →State the name of particle X.
See it on the paper →A nucleus of radium-228 undergoes a series of decays to form nucleus X. During the process, 5 α-particles and 4 β – particles are emitted. Determine the number of protons and the number of neutrons in nucleus X. number of protons =
See it on the paper →Complete the equation to represent the radioactive decay of tritium. 3 1 H He + β + 0 X (i)
See it on the paper →State the name of particle X.
See it on the paper →Determine a value for the wavelength of the gamma radiation emitted during the decay of the uranium-238 nucleus. wavelength = m
See it on the paper →In practice, the rebound kinetic energy of the thorium nucleus is not negligible. Explain, without further calculation, how your answer in (b)(ii) compares with the true wavelength of gamma radiation emitted during the decay of the uranium-238 nucleus.
See it on the paper →Gamma radiation emitted during the decay of a sample of uranium-238 has a single wavelength. 60 Nuclei of cobalt-60 ( 27 Co) decay by beta emission, and also emit gamma radiation in the process. Suggest why there is not a single wavelength for the gamma radiation emitted during the decay of a sample of cobalt-60.
See it on the paper →Determine a value for the wavelength of the gamma radiation emitted during the decay of the uranium-238 nucleus. wavelength = m
See it on the paper →In practice, the rebound kinetic energy of the thorium nucleus is not negligible. Explain, without further calculation, how your answer in (b)(ii) compares with the true wavelength of gamma radiation emitted during the decay of the uranium-238 nucleus.
See it on the paper →Gamma radiation emitted during the decay of a sample of uranium-238 has a single wavelength. 60 Nuclei of cobalt-60 ( 27 Co) decay by beta emission, and also emit gamma radiation in the process. Suggest why there is not a single wavelength for the gamma radiation emitted during the decay of a sample of cobalt-60.
See it on the paper →Nitrogen-12 ( 7 N) is an unstable isotope of nitrogen that decays by the emission of radiation 12 to carbon-12 ( 6 C). Complete the full nuclear equation for the decay, including all the particles involved. 12 7 N
See it on the paper →Comprehensive responses • Candidates correctly identified alpha-decay. Limited responses • The most common incorrect response was beta-plus decay.
— Examiner report, February/March 2026, 9702/22 Q7(b)(i) (Cambridge)
Comprehensive responses • Candidates correctly identified beta-minus decay. Limited responses • Both beta-plus and just ‘beta’ were common incorrect answers. • Candidates who use the symbol should be careful to make clear whether they are referring to –plus or –minus decay.
— Examiner report, February/March 2026, 9702/22 Q7(b)(ii) (Cambridge)
Comprehensive responses • Candidates correctly stated that radioactive decay is the spontaneous emission of ionising radiation from unstable nuclei. Limited responses • Many candidates did realise that radioactive decay is something that happens to unstable nuclei. • Candidates were often unclear about what was being emitted or that the emission is spontaneous. • Some candidates gave descriptions...
— Examiner report, February/March 2026, 9702/42 Q9(a) (Cambridge)
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