Particle model of matter

Scope and route

Shared: Physics and Trilogy, both tiers unless a Higher branch is named.
Separate Physics: Outside the Trilogy physics requirements.
Higher: Higher-only objectives, examples or assessments are labelled.
Ratings: Difficulty 1–4 and duration are proposed design choices; mastery means independently meeting exit criteria.

Area page →

PM-U1 · Density and states

Unit page →

PM-01 · PM-U1 · Planned

Density and particle arrangements

ScopeShared
Difficulty2 / 4 · proposed
Time25–30 min · estimated
StatusPlanned

Learning objectives

Calculate density and explain state differences using arrangements/separations without changing particle size.

8463 §§4.3.1.1 / 8464 §§6.3.1.1

DfE single-science pp.42–43 / Combined pp.35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,4.5; MS3b,3c,5c.

Needs firstP0

Explanation

Density compares mass with occupied volume. State models describe particle arrangements and spacing; changes in bulk density need not mean particles change size. A large object can have low density even if its total mass is high.

Concepts, equations and units: ρ=m/V; kg/m³; mass kg, volume m³; solid/liquid/gas models.

Prediction, demonstration and game exercise

Predict, observe, explain

Compare equal-volume solids and equal-mass objects; reveal annotated particle spacing.

Planned learner game exercise

Choose a material for a target mass/volume and classify three particle diagrams.

Independent practice

Three density problems with cm³ conversions and a model limitation explanation.

Original practice example · Shared

A sample has mass 0.20 kg and volume 0.00010 m³. Find density.

Show working and model answer

Working / reasoning

ρ = m/V = 0.20/0.00010.

Answer

2000 kg/m³.

Exit check and success criteria

Two correct calculations with units and correct three state diagrams.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Particles expand when material expands; denser always means larger particles; density and mass are identical.

Practical preparation

Preparation for RP-P5/RP-C17, AT1.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

PM-02 · PM-U1 · Planned

Measuring density: solids and liquids

ScopeShared
Difficulty3 / 4 · proposed
Time35–40 min · estimated
StatusPlanned

Learning objectives

Select methods for regular solids, irregular solids and liquids; evaluate volume/mass errors.

8463 §§4.3.1.1;8.2.5 / 8464 §§6.3.1.1;10.2.17

DfE single-science pp.42–43 / Combined pp.35. Evidence checked 30 September–1 October 2026. Skills: WS2.3–2.7,3.4,3.7; MS2a,2b,3c,5c.

Needs firstPM-01

Explanation

Regular solids can use dimensions; irregular solids can use displaced volume if the method is suitable. A liquid needs its mass without the container and a measured volume. Tare, meniscus and trapped-air errors affect the result.

Concepts, equations and units: ρ=m/V; cube/cuboid volume from lengths; displacement volume; tare/subtraction for liquid mass; kg/m³ or g/cm³ converted explicitly.

Prediction, demonstration and game exercise

Predict, observe, explain

Use balance, ruler and displacement vessel; show meniscus/parallax and trapped air errors.

Planned learner game exercise

Measure all three sample types virtually; reject unsuitable methods and collect repeats.

Independent practice

Three density estimates, uncertainty comparisons and a method improvement.

Original practice example · Shared

A container weighs 50 g empty and 130 g with 100 cm³ of liquid. Find liquid density.

Show working and model answer

Working / reasoning

Liquid mass = 130 − 50 = 80 g; ρ = 80/100 = 0.80 g/cm³.

Answer

0.80 g/cm³, equivalent to 800 kg/m³.

Exit check and success criteria

Correct methods for every sample type plus two valid densities and one quantified uncertainty estimate.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Liquid density uses container mass; displacement volume is total water volume; repeat readings correct a mis-zeroed balance.

Practical preparation

RP-P5/RP-C17; regular/irregular solids and liquids; AT1.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

PM-U2 · Internal energy and state changes

Unit page →

PM-03 · PM-U2 · Planned

Internal energy, temperature and heating

ScopeShared
Difficulty2 / 4 · proposed
Time25–30 min · estimated
StatusPlanned

Learning objectives

Distinguish internal energy and temperature; relate heating to kinetic/potential particle energy changes.

8463 §§4.3.2.1–4.3.2.2 / 8464 §§6.3.2.1–6.3.2.2

DfE single-science pp.42–43 / Combined pp.35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,3.6; MS3b,3c.

Needs firstEN-08,PM-01

Explanation

Internal energy includes the kinetic and potential energies of all particles. Temperature relates to particle motion but does not measure the total internal energy of a sample. Equal temperature does not imply equal energy when masses or materials differ.

Concepts, equations and units: Internal energy=sum particle kinetic and potential energies; ΔE=mcΔθ for temperature change without phase change; J,kg,J/(kg °C),°C.

Prediction, demonstration and game exercise

Predict, observe, explain

Compare samples at equal temperature but different mass; interpret particle animation as a model.

Planned learner game exercise

Give equal thermal inputs to selectable samples; predict temperature change then annotate particle changes.

Independent practice

Two ΔE calculations and an explanation of equal temperature/different internal energy.

Original practice example · Shared

Two samples of the same material are at the same temperature, but one has twice the mass. Must their internal energies be equal?

Show working and model answer

Working / reasoning

No: temperature is not total internal energy, and the larger sample contains more particles under comparable conditions.

Answer

No; the larger sample has a greater total internal energy under the stated comparable conditions.

Exit check and success criteria

Both calculations correct and internal energy includes both particle contributions.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Temperature measures total energy; heat is contained as a substance; particles get bigger when heated.

Practical preparation

RP-P1/RP-C14 conceptual revisit; no additional RP.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

PM-04 · PM-U2 · Planned

Changes of state and latent heat

ScopeShared
Difficulty3 / 4 · proposed
Time30–35 min · estimated
StatusPlanned

Learning objectives

Explain reversible state changes and mass conservation; calculate latent energy; interpret heating/cooling plateaux.

8463 §§4.3.1.2,4.3.2.3 / 8464 §§6.3.1.2,6.3.2.3

DfE single-science pp.42–43 / Combined pp.35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,3.5; MS3c,3d,4a.

Needs firstPM-03

Explanation

During a state change, energy changes particle separation/interaction potential energy while temperature can remain constant. Specific latent heat is energy per kilogram for that change. In ordinary reversible state changes, total mass is conserved.

Concepts, equations and units: E=mL; J,kg,L in J/kg; latent fusion/vaporisation; constant-temperature phase change at stated pressure.

Prediction, demonstration and game exercise

Predict, observe, explain

Heat a fixed mass through melting and boiling; reveal energy input with constant-temperature intervals.

Planned learner game exercise

Allocate energy to a sample across states; label solid, liquid, gas and mixed-phase intervals.

Independent practice

Three latent-heat calculations and a temperature–time graph explanation, including cooling.

Original practice example · Shared

Melt 0.20 kg of a solid with latent heat 100,000 J/kg at its melting point. Find energy required.

Show working and model answer

Working / reasoning

E = mL = 0.20 × 100,000.

Answer

20,000 J.

Exit check and success criteria

Two values correct, plateau linked to potential-energy change and mass conserved.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Temperature always rises when heating; particles vanish on evaporation; latent heat means no energy transfer.

Practical preparation

Optional teacher-supervised heating/cooling demonstration; not an RP.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

PM-U3 · Gas motion and pressure

Unit page →

PM-05 · PM-U3 · Planned

Gas motion, temperature and pressure

ScopeShared
Difficulty2 / 4 · proposed
Time25–30 min · estimated
StatusPlanned

Learning objectives

Explain pressure from random particle collisions; predict pressure rise when fixed-volume gas warms.

8463 §§4.3.3.1 / 8464 §§6.3.3.1

DfE single-science pp.42–43 / Combined pp.35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,3.5,3.6; MS4a.

Needs firstPM-03

Explanation

Gas particles move randomly and exert forces through collisions with walls. At fixed volume, heating increases average kinetic energy, increasing pressure through more frequent and stronger collisions. A pressure–temperature proportionality must not use Celsius as though zero Celsius meant zero particle motion.

Concepts, equations and units: Gas pressure Pa; temperature °C used qualitatively; average kinetic energy rises with temperature; fixed mass/volume conditions.

Prediction, demonstration and game exercise

Predict, observe, explain

Warm a sealed fixed-volume model gas; count wall collision impulses with animation slowed and labelled.

Planned learner game exercise

Choose warmer/cooler settings and compare pressure readings; explain constraints of particle representation.

Independent practice

Interpret pressure–temperature data qualitatively and write a collision-based explanation.

Original practice example · Shared

A sealed rigid gas container warms. Explain the pressure change without changing particle size.

Show working and model answer

Working / reasoning

Average kinetic energy/speed increases; collisions with the wall are more frequent and forceful, increasing force per unit area.

Answer

Pressure rises at fixed mass and volume because wall-collision forces increase.

Exit check and success criteria

Explain higher average speed/more forceful and frequent wall collisions at fixed volume; avoid unsupported proportionality in °C.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Gas pressure is caused by particles pressing without motion; pressure rises because particles expand; p∝temperature in °C.

Practical preparation

Optional teacher-led pressure/temperature demonstration; no RP.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

PM-06 · PM-U3 · Planned

Gas pressure and volume

ScopeSeparate Physics
Difficulty3 / 4 · proposed
Time30–35 min · estimated
StatusPlanned

Learning objectives

Use fixed-mass constant-temperature gas data to calculate pressure/volume changes; explain the inverse relation.

8463 §§4.3.3.2 / No Trilogy counterpart

DfE single-science pp.42–43 / Combined pp.35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,2.2; MS3b,3c,4a.

Needs firstPM-05

Explanation

The pV relation requires a fixed amount of gas at constant temperature. Reducing volume raises collision frequency at the walls and increases pressure. If the gas also warms, the same fixed pV model does not apply.

Concepts, equations and units: pV=constant, p1V1=p2V2; Pa,m³; mass and temperature held fixed.

Prediction, demonstration and game exercise

Predict, observe, explain

Compress a model slowly while heat exchange holds temperature fixed; compare collision frequency.

Planned learner game exercise

Set syringe volume for a target pressure and select only constant-temperature datasets.

Independent practice

Three p/V problems and a p–V graph; optional p–1/V straight line.

Original practice example · Separate Physics

A gas at 100 kPa occupies 0.002 m³. It compresses to 0.001 m³ at constant temperature. Find pressure.

Show working and model answer

Working / reasoning

p2 = p1V1/V2 = 100 × 0.002/0.001 kPa.

Answer

200 kPa.

Exit check and success criteria

Two values correct and both validity conditions stated.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

pV remains constant while temperature changes; volume halves so pressure halves.

Practical preparation

Optional teacher-supervised syringe/data investigation; not an RP.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

PM-07 · PM-U3 · Planned

Work done on a gas

ScopeSeparate Physics Higher
Difficulty3 / 4 · proposed
Time25–30 min · estimated
StatusPlanned

Learning objectives

Explain why rapid compression can heat gas; distinguish this from the constant-temperature pV model.

8463 §§4.3.3.3 / No Trilogy counterpart

DfE single-science pp.42–43 / Combined pp.35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,3.6,3.7.

Needs firstPM-06,EN-07

Explanation

Compressing gas does mechanical work on it. If transfer to surroundings is too slow to remove that added energy, internal energy and temperature increase. This is different from a slow constant-temperature compression model.

Concepts, equations and units: Mechanical work increases internal energy; J,Pa,°C; no pΔV calculation required.

Prediction, demonstration and game exercise

Predict, observe, explain

Compare slow isothermal and fast model pump strokes; trace transfer pathway and temperature change.

Planned learner game exercise

Select compression and heat-exchange conditions, predict final temperature direction and justify observed data.

Independent practice

Write a bicycle-pump explanation and critique use of pV=constant across unequal temperatures.

Original practice example · Separate Physics Higher

Why can rapid use of a bicycle pump warm its enclosed gas?

Show working and model answer

Working / reasoning

A force does work compressing the gas, transferring energy into its internal energy before it can fully transfer out.

Answer

Work increases internal energy and can increase temperature; pV need not stay constant.

Exit check and success criteria

Causal work → internal energy → temperature explanation and correct rejection of isothermal equation in rapid-heating case.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Compression always keeps temperature constant; hotter pump proves energy creation.

Practical preparation

Optional teacher-led bicycle-pump demonstration; not an RP.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

Sources and full programme

Sources checked 30 September–1 October 2026. Specifications govern content; textbooks supplement it. England has no single prescribed Physics course book. The full planning document includes sourced comparisons of Collins separate Physics and Trilogy books, Hodder/Hachette Physics and Oxford Physics listings, with access/approval limitations.

Download the complete Markdown programme and coverage matrix

A subsection map is proposed coverage. Clause-level educator review, item moderation, model validation and hands-on provision remain release gates. No all-board alignment or exam-board endorsement is claimed.