AS & A Level Physics 9702 · Topic 11

Particle physics: past paper questions

281 real questionsasked in 9 of the last 10 exam series2019–2025usually: State, Determine, Calculate, Use, Explain

Real questions on particle physics

The newest 20 of 184 written questions, plus 97 multiple-choice. Open one to see it on the real paper.

9702/21 · October/November 2025 · Q6a(i)[2]
Determine the numbers of protons, neutrons and electrons in a neutral atom of tritium. number of neutrons = number of protons =
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9702/21 · October/November 2025 · Q6a(ii)[2]
Draw a labelled diagram to represent a simple model of the arrangement of the protons, neutrons and electrons in a tritium atom. (ii)
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9702/21 · October/November 2025 · Q6c[2]
Determine the quark composition of a tritium nucleus.
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9702/22 · October/November 2025 · Q6a[1]
State what is meant by a fundamental particle.
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9702/22 · October/November 2025 · Q6b(i)[2]
Particle Q is a meson with a charge of 0. Determine a possible quark composition for Q.
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9702/22 · October/November 2025 · Q6b(ii)[3]
Calculate the speed of particle Q. speed = m s –1 Particle Q has a mass of 0.67 u and a kinetic energy of 2.1 × 10 –16 J. (ii)
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9702/22 · October/November 2025 · Q6c(i)[1]
State the number of electrons in a neutral atom of radium-228. number of electrons =
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9702/22 · October/November 2025 · Q6c(ii)[2]
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 =
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9702/23 · October/November 2025 · Q6a(i)[2]
Determine the numbers of protons, neutrons and electrons in a neutral atom of tritium. number of neutrons = number of protons =
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9702/23 · October/November 2025 · Q6a(ii)[2]
Draw a labelled diagram to represent a simple model of the arrangement of the protons, neutrons and electrons in a tritium atom. (ii)
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9702/21 · May/June 2025 · Q7a[3]
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
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9702/21 · May/June 2025 · Q7b(i)[1]
State the charge on the positron in terms of the elementary charge e. charge = e
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9702/21 · May/June 2025 · Q7b(ii)[1]
State the group (class) of fundamental particle to which the positron belongs. (ii)
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9702/21 · May/June 2025 · Q7b(iii)[3]
In Table 7.1, state the flavour and charge of the three antiquarks that comprise the antiproton. Table 7.1 flavour charge / e (iii)
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9702/22 · May/June 2025 · Q7a[1]
State what is meant by a fundamental particle.
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9702/22 · May/June 2025 · Q7b(ii)[3]
Nucleus X undergoes β – decay to form nucleus Z. Complete the equation representing this decay. X Z + +
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9702/22 · May/June 2025 · Q7c[2]
A sample of a radioactive substance emits particles that are positively charged and have a continuous range of kinetic energies. State and explain whether the nuclei in the sample are undergoing α-decay, β + decay or β – decay.
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9702/23 · May/June 2025 · Q8a[3]
An antiparticle equivalent of the neutron is called the antineutron. The quarks in the antineutron are the antiparticles of the quarks in a neutron. The elementary charge is e. In Table 8.1, state the flavour and charge of the three antiquarks that comprise the antineutron. Table 8.1 flavour charge / e
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9702/23 · May/June 2025 · Q8b[2]
In β − decay, a neutron decays to form a proton. Suggest the names of the particle and the antiparticle. particle: Theory predicts that an antineutron should decay to form an antiproton. A particle and an antiparticle should also be observed.
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9702/41 · May/June 2025 · Q2b(i)[1]
State the charge on the nucleus, in terms of the elementary charge e. charge = e
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What examiners said

The phrase ‘not fundamental’ seemed to confuse some candidates. A small proportion of the candidates appeared to misread the question and underlined only particles that were fundamental.
— Examiner report, October/November 2023, 9702/22 Q7(a) (Cambridge)

Most candidates were able to apply the conservation of nucleon number to determine that 6 α-particles would be emitted during the sequence of decays. Fewer candidates were able to apply conservation of charge to determine the number of β– particles that would also be emitted.
— Examiner report, October/November 2023, 9702/22 Q7(b) (Cambridge)

Although this was very straightforward for stronger candidates, some of the weaker candidates had not learnt the basic knowledge needed to answer the question. Some confused a meson with a baryon. Weaker candidates could have improved by a more thorough learning of the charges of the different flavours of quarks and antiquarks.
— Examiner report, October/November 2023, 9702/22 Q7(c) (Cambridge)

Practise this topic

Answer these questions online and get each one marked against the official mark scheme, with what you missed and how to fix it.

Practise particle physics

In the syllabus

11.1 Atoms, nuclei and radiation

infer from the results of the α-particle scattering experiment the existence and small size of the nucleus
describe a simple model for the nuclear atom to include protons, neutrons and orbital electrons
distinguish between nucleon number and proton number
understand that isotopes are forms of the same element with different numbers of neutrons in their
understand and use the notation AZ X for the representation of nuclides
understand that nucleon number and charge are conserved in nuclear processes
describe the composition, mass and charge of α-, β- and γ-radiations (both β – (electrons) and β+
understand that an antiparticle has the same mass but opposite charge to the corresponding particle,
state that (electron) antineutrinos are produced during β – decay and (electron) neutrinos are produced
understand that α-particles have discrete energies but that β-particles have a continuous range of
represent α- and β-decay by a radioactive decay equation of the form 238
U " 234

11.2 Fundamental particles

understand that a quark is a fundamental particle and that there are six flavours (types) of quark: up,
recall and use the charge of each flavour of quark and understand that its respective antiquark has the
recall that protons and neutrons are not fundamental particles and describe protons and neutrons in
understand that a hadron may be either a baryon (consisting of three quarks) or a meson (consisting of
describe the changes to quark composition that take place during β – and β+ decay
recall that electrons and neutrinos are fundamental particles called leptons

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