O Level Physics 5054 · Topic 5

Nuclear physics: past paper questions

225 real questionsasked in 10 of the last 10 exam series2019–2025usually: State, Describe, Explain, Determine, Complete

Real questions on nuclear physics

The newest 20 of 156 written questions, plus 69 multiple-choice. Open one to see it on the real paper.

5054/21 · October/November 2025 · Q8a[2]
Describe how the composition of an atom of radon-222 differs from that of an atom of radon-224.
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5054/21 · October/November 2025 · Q8c(i)[2]
Describe what is observed when the detector is at position J and when it is at position K. position J position K
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5054/21 · October/November 2025 · Q8c(ii)[2]
Explain what these observations show about the structure of a gold atom.
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5054/22 · October/November 2025 · Q8a(i)[1]
State one way in which the compositions of the atoms of all lithium isotopes are the same.
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5054/22 · October/November 2025 · Q8a(ii)[1]
State one way in which the composition of a lithium atom of one isotope is different from the composition of a lithium atom of a different isotope.
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5054/22 · October/November 2025 · Q8b(i)[2]
The nuclide symbols for isotopes of lithium are represented as XY Li where X and Y are numbers. Determine the values of X and Y for the isotope represented by Fig. 8.1. X = (i)
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5054/22 · October/November 2025 · Q8b(ii)[1]
An ion of this isotope of lithium has a single positive charge and is represented as ( XY Li + ). Describe how the diagram that represents this ion differs from Fig. 8.1.
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5054/22 · October/November 2025 · Q8c(i)[1]
State one damaging effect of nuclear radiation.
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5054/22 · October/November 2025 · Q8c(ii)[2]
The emission of radioactive radiation from an unstable isotope is described as random and spontaneous. State what is meant by ‘random’ and what is meant by ‘spontaneous’. random spontaneous
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5054/21 · May/June 2025 · Q8a[2]
State the names of the types of particles found in a nucleus of plutonium-239, and state how many there are of each type.
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5054/21 · May/June 2025 · Q8b(i)[2]
Explain how the fission process produces a chain reaction. (i)
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5054/21 · May/June 2025 · Q8b(ii)[2]
Explain how control rods are used to increase and decrease the rate of the chain reaction in a nuclear reactor.
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5054/21 · May/June 2025 · Q8c[2]
Plutonium-239 decays by the emission of an alpha particle (α-particle). State two differences between an alpha particle and a beta particle (β-particle). difference difference
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5054/21 · May/June 2025 · Q8d(i)[2]
Draw a labelled diagram of either a cloud chamber or a spark counter. Label the position of the radioactive source with an S.
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5054/22 · May/June 2025 · Q8a[3]
In Table 8.1 state the purpose of each part of the reactor. part purpose container vessel to withstand high pressures and temperatures and make sure no coolant escapes Table 8. concrete shielding control rods moderator
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5054/22 · May/June 2025 · Q8b[3]
Describe what causes the fission of a single nucleus of uranium-235 in the fuel rods, and describe what happens during the fission.
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5054/21 · October/November 2024 · Q8a[1]
Explain why hydrogen-3 cannot decay by the emission of alpha particles.
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5054/21 · October/November 2024 · Q8b(i)[3]
Complete the nuclide equation for the decay of hydrogen-3. 3 1 H β + Q
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5054/21 · October/November 2024 · Q8b(ii)[1]
State the name of the element represented by Q.
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5054/21 · October/November 2024 · Q8c(i)[2]
Define ‘half-life’. (i)
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What examiners said

Most candidates correctly stated the difference between a neutral atom of U-235 and a neutral atom of U-238 in terms of the number of neutrons in the nucleus of these atoms.
— Examiner report, October/November 2023, 5054/21 Q8(a) (Cambridge)

Many candidates were able to explain what happens to the nucleus of an atom during fission. Other candidates confused fission with radioactive decay.
— Examiner report, October/November 2023, 5054/21 Q8(b)(i) (Cambridge)

Few candidates knew the sequence of events explaining how fission can lead to a chain reaction in the reactor in a power station. The idea that fission neutrons are absorbed by other U-235 nuclei, which themselves split and release further neutrons, was rarely seen.
— Examiner report, October/November 2023, 5054/21 Q8(b)(ii) (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 nuclear physics

In the syllabus

5.1 The nuclear model of the atom

Describe the structure of the atom in terms of a positively charged nucleus and negatively charged electrons in orbit around the nucleus
Describe how alpha-particle scattering experiments provide evidence for: (a) a very small nucleus surrounded by mostly empty space (b) a nucleus containing most of the mass of the atom (c) a nucleus that is positively charged Describe the composition of the nucleus in terms of protons and neutrons Describe how atoms form positive ions by losing electrons or negative ions by gaining electrons
Define the terms proton number (atomic number) Z and nucleon number (mass number) A and be able to calculate the number of neutrons in a nucleus A
Explain the term nuclide and use the nuclide notation Z X
Explain what is meant by an isotope and state that an element may have more than one isotope

5.2 Radioactivity

Describe the detection of alpha particles (α-particles) using a cloud chamber or spark counter and the detection of beta particles (β-particles) (β-particles will be taken to refer to β−) and gamma radiation (γ-radiation) by using a Geiger-Müller tube and counter
Use count rate measured in counts / s or counts / minute
Know what is meant by background radiation
Know the sources that make a significant contribution to background radiation including: (a) radon gas (in the air) (b) rocks and buildings (c) food and drink (d) cosmic rays
Use measurements of background radiation to determine a corrected count rate Describe the emission of radiation from a nucleus as spontaneous and random in direction Describe α-particles as two protons and two neutrons (helium nuclei), β-particles as high-speed electrons from the nucleus and γ-radiation as high-frequency electromagnetic waves State, for α-particles, β-particles and γ-radiation: (a) their relative ionising effects (b) their relative penetrating powers Describe the deflection of α-particles, β-particles and γ-radiation in electric fields and magnetic fields Know that radioactive decay is a change in an unstable nucleus that can result in the emission of α-particles or β-particles and/or γ-radiation and know that these changes are spontaneous and random Use decay equations, using nuclide notation, to show the emission of α-particles, β-particles and γ-radiation Describe the process of fusion as the formation of a larger nucleus by combining two smaller nuclei with the release of energy, and recognise fusion as the energy source for stars Describe the process of fission when a nucleus, such as uranium-235 (U-235), absorbs a neutron and produces daughter nuclei and two or more neutrons with the release of energy Explain how the neutrons produced in fission create a chain reaction and that this is controlled in a nuclear reactor, including the action of coolant, moderators and control rods

5.2 Radioactivity continued

Define the half-life of a particular isotope as the time taken for half the nuclei of that isotope in any sample to decay; recall and use this definition in calculations, which may involve information in tables or decay curves
Describe the dating of objects by the use of 14C
Explain how the type of radiation emitted and the half-life of the isotope determine which isotope is used for applications including: (a) household fire (smoke) alarms (b) irradiating food to kill bacteria (c) sterilisation of equipment using gamma rays (d) measuring and controlling thicknesses of materials with the choice of radiations used linked to penetration and absorption (e) diagnosis and treatment of cancer using gamma rays State the effects of ionising nuclear radiations on living things, including cell death, mutations and cancer Explain how radioactive materials are moved, used and stored in a safe way, with reference to: (a) reducing exposure time (b) increasing distance between source and living tissue (c) use of shielding to absorb radiation

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