Numbers
OCR A-Level Physics A H556
Practical Skills in the Written Papers
The Practical Endorsement
Topic overviewAnalogue and digital measuring instrumentsImproving accuracy with repeat timing, fiducial markers and plumb linesTiming, calipers and micrometersConstructing and testing circuitsSignal generators and oscilloscopesGenerating and measuring wavesData loggers, modelling software and ionising radiation
Physical Quantities and Units
Making Measurements and Analysing Data
Nature of Quantities
Motion
Forces in Action
Work, Energy and Power
Materials
Newton’s Laws of Motion and Momentum
Charge and Current
Energy, Power and Resistance
Electrical Circuits
Waves
Topic overviewProgressive waves and their propertiesThe wave equationReflection, refraction and diffractionWave graphs and intensityThe electromagnetic spectrumPolarisationRefraction and refractive indexCritical angle and total internal reflectionThe principle of superpositionInterference, coherence and path differenceTwo-source interference, Young's double-slit experiment and the diffraction gratingForming stationary wavesStationary waves on strings and in air columnsMeasuring the speed of soundNode spacing, amplitude and phase in stationary wavesHarmonics and the fundamental mode
Quantum Physics
Thermal Physics
Topic overviewThermal equilibrium and absolute temperatureThe kinetic model of solids, liquids and gasesBrownian motion and internal energySpecific heat capacityMeasuring specific heat capacitySpecific latent heatMeasuring specific latent heatMoles, the Avogadro constant and kinetic theoryGas laws, the ideal gas equation and r.m.s. speedMaxwell-Boltzmann distribution, Boltzmann constant and internal energy
Oscillations
Gravitational Fields
Astrophysics and Cosmology
Topic overviewThe solar system and the birth of a starThe death of a low-mass starSupernovae, neutron stars and black holesThe Hertzsprung-Russell diagramEnergy levels and emission spectraAbsorption spectra and spectral linesPhoton energy and the diffraction gratingWien's law and Stefan's lawAstronomical distances, parallax and the cosmological principleDoppler shift and Hubble's lawThe expanding universe and the Big BangEvidence for the Big Bang and dark energy
Capacitors
Topic overviewCapacitance and charging a capacitorCapacitors in seriesCapacitors in parallel and combined circuitsEnergy stored by a capacitorCharging and discharging through a resistorInvestigating capacitor dischargeThe time constantIterative modelling, exponential decay and the constant-ratio property
Electric Fields
Electromagnetism
Nuclear and Particle Physics
Topic overviewAlpha-particle scattering and the nuclear modelProton number, nucleon number and isotopesThe strong nuclear force and nuclear radiusParticles, antiparticles and hadronsLeptons and the quark modelQuark composition and chargesBeta decay in the quark modelRadioactive decay and the three radiationsNuclear decay equationsActivity, decay constant and half-lifeExponential decay and radioactive datingMass-energy equivalenceAnnihilation, mass defect and binding energyBinding energy per nucleon and induced fissionThe fission reactor and nuclear wasteNuclear fusion and balancing nuclear equations
Nuclear and Particle Physics
- 16 subtopics
- 47 things to know
- Papers 1, 2 and 3
What Nuclear and Particle Physics covers
Inside the atom: the evidence for the nucleus, quarks and leptons, radioactive decay and its mathematics, and the energy released by fission and fusion.
Where it is assessed
Papers 1, 2 and 3
Newtonian world, astrophysics and particles, drawn on across the papers.
Check the OCR specification ↗The 16 subtopics
Each one has its own page.
- Alpha-particle scattering and the nuclear modelRecall questions on the alpha-particle scattering experiment and what it showed, the simple nuclear model, and the orders of magnitude of atomic and nuclear radii.Open →
- Proton number, nucleon number and isotopesRecall questions on proton number and nucleon number, the femtometre, protons, neutrons and electrons with their charges, isotopes and nuclear notation.Open →
- The strong nuclear force and nuclear radiusRecall questions on the range and behaviour of the strong force, R = r₀A^(1/3), and the density of nuclear matter.Open →
- Particles, antiparticles and hadronsRecall questions on particles and antiparticles, the positron, antiproton and antineutron, and classifying protons, neutrons and electrons as hadrons or leptons.Open →
- Leptons and the quark modelRecall questions on the electron and neutrino as leptons, and on the simple quark model of hadrons.Open →
- Quark composition and chargesRecall questions on the charges of up, down and strange quarks and antiquarks, and the quark composition and overall charge of protons and neutrons.Open →
- Beta decay in the quark modelRecall questions on the particles emitted in beta-minus and beta-plus decay, the nucleon and quark changes involved, and balancing quark transformation equations.Open →
- Radioactive decay and the three radiationsRecall questions on the spontaneous and random nature of decay, the composition, range, ionising power and absorbers of alpha, beta and gamma radiation, and the radiation absorption experiment.Open →
- Nuclear decay equationsRecall questions on how nucleon and proton numbers change in alpha, beta-minus and beta-plus decay, the general alpha decay equation, and the quantities conserved when balancing nuclear equations.Open →
- Activity, decay constant and half-lifeRecall questions on activity and A = λN, the decay constant, half-life and its calculation, the protactinium experiment to find half-life, and the straight-line graph used to find the decay constant.Open →
- Exponential decay and radioactive datingRecall questions on the exponential decay equations for activity and undecayed nuclei, modelling decay with dice and spreadsheets, and carbon dating and how the age of a sample is calculated.Open →
- Mass-energy equivalenceRecall questions on E = mc², energy released from the mass difference in a nuclear reaction, and the steps of calculating that energy.Open →
- Annihilation, mass defect and binding energyRecall questions on annihilation and pair creation, the minimum photon energy for pair creation, mass defect, binding energy and the steps of calculating binding energy.Open →
- Binding energy per nucleon and induced fissionRecall questions on binding energy per nucleon and its calculation, the binding energy curve and iron-56, why fusion and fission release energy, induced fission, chain reactions and slowing neutrons.Open →
- The fission reactor and nuclear wasteRecall questions on fuel rods, control rods, moderators, nuclear waste and its environmental risks, and the decisions involved in building nuclear power stations.Open →
- Nuclear fusion and balancing nuclear equationsRecall questions on nuclear fusion and the temperatures and plasma it requires, and conserving nucleon and proton numbers, electron values and neutrinos when balancing nuclear equations.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Define proton number, nucleon number and isotopes.
Numbers
Explain why the total charge of a proton equals +e using the charges of its constituent quarks.
Numbers
State the iterative equation used for modelling radioactive decay, and the initial values that must be set when modelling it on a spreadsheet.
Key term
How are the masses of reactants and products found when calculating the energy from a nuclear reaction, and what happens when a particle meets its antiparticle?
Key term
Which two quantities must be conserved when balancing nuclear transformation equations?
Numbers
Up to what nucleon separation is the strong nuclear force attractive?
Numbers
State the formula for the radius of a nucleus and define each term.
Key term
Why are electrons classified as leptons rather than hadrons?
Numbers
State the general form of the nuclear equation for alpha decay.
Key term
What two quantities must be conserved (balanced) in any nuclear transformation equation?
Key term
What is the decay constant λ?
Numbers
State the equation relating half-life to decay constant.
Numbers
State the exponential decay equation for the number of undecayed nuclei N at time t.
Numbers
State the equation that relates binding energy to mass defect.
Key term
Name three common moderator materials used in nuclear reactors.
Evaluation
What does nuclear waste consist of?
Key term
What order of magnitude of temperature is required for nuclear fusion?
Key term
What was observed for most alpha particles in the gold foil scattering experiment, and what does this indicate about atomic structure?
Key term
What happened to a small fraction of alpha particles in the scattering experiment?
Key term
Define a hadron in terms of the fundamental forces it experiences.
Key term
Apart from the electron, what other particle is emitted in beta-minus decay?
Key term
Define leptons in terms of the fundamental forces they experience.
Key term
State the quark composition of a proton.
Key term
At the quark level, which quark changes into which other quark during beta-minus decay?
Key term
At the quark level, which quark transformation occurs during beta-plus decay?
Key term
What are gamma rays and what properties do they have regarding charge and mass?
Key term
What thickness and type of material is needed to stop beta particles?
Key term
What does Einstein's mass–energy equation state about the relationship between energy and mass?
Key term
In the equation E = mc², what does each symbol represent?
Key term
In particle–antiparticle annihilation, what form does the released energy take?
Key term
When calculating energy from a nuclear reaction, what must be determined for the products?
Key term
Why does the deflection of alpha particles indicate that the nucleus is positively charged?
Key term
What is a neutron and what is its relative charge?
Key term
What is the strong nuclear force?
Key term
Apart from the positron, what other particle is emitted in beta-plus decay?
Key term
Which quarks and antiquarks are used in the simple quark model to describe hadrons?
Key term
State the quark composition of a neutron.
Key term
What materials and thicknesses are required to significantly reduce gamma radiation?
Key term
What is the composition of an alpha particle?
Key term
When investigating radiation absorption, why should the source be positioned at a fixed distance from the detector?
Key term
What is a beta-minus particle and how is it produced?
Key term
What is the value of the speed of light c used in Einstein's mass–energy equation?
Key term
What is the minimum photon energy required for pair creation, expressed in terms of the particle's rest mass?
Key term
When calculating the binding energy of a nucleus, what nuclear composition must first be determined?
Key term
What fissile materials are typically contained in the fuel rods of a fission reactor?
Key term
Define nuclear fusion.
Take Nuclear and Particle Physics further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Activity vs Count rate
Activity: decays occurring per unit time. Count rate: detected events occurring per unit time.
Half-life vs Decay constant
Half-life: time for activity or undecayed nuclei to halve. Decay constant: probability of decay per nucleus per unit time.
Fission vs Fusion
Fission: heavy nucleus splitting into smaller nuclei. Fusion: light nuclei combining into a heavier nucleus.
Questions from this topic
Each one with the model answer underneath.
- 1
Describe the experimental setup used in the alpha-particle scattering experiment.
Model answer
Alpha particles were fired at a thin gold foil, and their deflections were observed using a detector that could be moved around the foil to different positions.
- 2
What was observed for most alpha particles in the gold foil scattering experiment, and what does this indicate about atomic structure?
Model answer
Most alpha particles passed straight through with little or no deflection, indicating that atoms are mostly empty space.
- 3
What happened to a small fraction of alpha particles in the scattering experiment?
Model answer
A small fraction were deflected through large angles, and very few were scattered back towards the source.
- 4
What evidence does large-angle scattering of alpha particles provide about atomic structure?
Model answer
It provides evidence that the positive charge and most of the mass of an atom is concentrated in a small central nucleus.
- 5
Why does the deflection of alpha particles indicate that the nucleus is positively charged?
Model answer
The nucleus must be positively charged because it repels the positively charged alpha particles, causing them to deflect.
- 6
Describe the simple nuclear model of the atom.
Model answer
The atom consists of a central nucleus containing protons and neutrons, surrounded by orbiting electrons.
What is inside Levo
Six ways to work the same material.
Nuclear and Particle Physics revision questions
- What does Nuclear and Particle Physics cover in OCR A-Level Physics A?
- 16 subtopics: alpha-particle scattering and the nuclear model, proton number, nucleon number and isotopes, the strong nuclear force and nuclear radius, particles, antiparticles and hadrons, leptons and the quark model, quark composition and charges, beta decay in the quark model, radioactive decay and the three radiations, nuclear decay equations, activity, decay constant and half-life, exponential decay and radioactive dating, mass-energy equivalence, annihilation, mass defect and binding energy, binding energy per nucleon and induced fission, the fission reactor and nuclear waste and nuclear fusion and balancing nuclear equations. Each one has its own page with questions and model answers.
- How is Nuclear and Particle Physics organised?
- By the OCR H556 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Nuclear and Particle Physics, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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