Particle model
2.1.2What the syllabus asks of you
- Describe, qualitatively, the particle structure of solids, liquids and gases, relating their properties to the forces and distances between particles and to the motion of the particles (atoms, molecules, ions and electrons)
- Describe the relationship between the motion of particles and temperature, including the idea that there is a lowest possible temperature (−273 °C), known as absolute zero, where the particles have least kinetic energy
- Describe the pressure and the changes in pressure of a gas in terms of the forces exerted by particles colliding with surfaces, creating a force per unit area
- Explain qualitatively, in terms of particles, the relationship between: (a) pressure and temperature at constant volume (b) volume and temperature at constant pressure (c) pressure and volume at constant temperature
- Recall and use the equation p1V1 = p2V2, including a graphical representation of the relationship between pressure and volume for a gas at constant temperature
Read the notes first
Chapter 2: Particle model
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Every question on Particle model, untimed, marked as you go.
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63 questions
1May / June 2026 · Paper 11 · Q17Show mark scheme →
A–196 °C
B–77 °C
C3.8 °C
D350 °C
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2May / June 2026 · Paper 12 · Q17Show mark scheme →
Aa gas being heated
Ba liquid being heated
Ca liquid undergoing solidification
Da solid being heated
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3May / June 2026 · Paper 12 · Q18Show mark scheme →
Amove closer together, decreases
Bmove closer together, increases
Cmove further apart, decreases
Dmove further apart, increases
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4Oct / Nov 2025 · Paper 11 · Q10Show mark scheme →
A1.2 × 10⁻⁴ m³
B4.8 × 10⁻⁴ m³
C1.2 × 10⁻² m³
D4.8 × 10⁴ m³
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5Oct / Nov 2025 · Paper 11 · Q15Show mark scheme →
Avolume-temperature graph showing a straight line with positive gradient starting above the origin
Bvolume-temperature graph showing a curve decreasing from a high value
Cvolume-temperature graph showing a straight line with negative gradient
Dvolume-temperature graph showing a horizontal line
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6Oct / Nov 2025 · Paper 12 · Q22Show mark scheme →
A0.50 × 10⁵ Pa
B0.90 × 10⁵ Pa
C1.1 × 10⁵ Pa
D1.9 × 10⁵ Pa
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7May / June 2025 · Paper 11 · Q14Show mark scheme →
AThe air molecules expand.
BThe air molecules bounce off each other more frequently.
CThe air molecules bounce off the walls more frequently.
DThe number of air molecules increases.
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8May / June 2025 · Paper 12 · Q13Show mark scheme →
Athe average force exerted on the piston each time that one air particle hits the piston
Bthe average speed of the air particles
Cthe mass of air inside the cylinder
Dthe number of collisions made by air particles with the piston in one second
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9May / June 2025 · Paper 12 · Q14Show mark scheme →
A80 kPa
B180 kPa
C80 000 kPa
D180 000 kPa
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10Oct / Nov 2024 · Paper 11 · Q7Show mark scheme →
Apressure
Bmass
Cfrequency of particle collision
Ddensity
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11Oct / Nov 2024 · Paper 11 · Q21Show mark scheme →
AAdding another 1.0 kg mass decreases the volume of the air by less than 10 cm³.
BAdding an additional 9.0 kg mass reduces the volume of the air to zero.
CThe pressure of the trapped air is less than atmospheric pressure when its volume is 90 cm³.
DThe temperature of the air decreases as the 1.0 kg mass is added.
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12Oct / Nov 2024 · Paper 12 · Q13Show mark scheme →
A0.69 × 10^5 N/m^2
B0.83 × 10^5 N/m^2
C1.2 × 10^5 N/m^2
D1.4 × 10^5 N/m^2
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13Oct / Nov 2024 · Paper 12 · Q14Show mark scheme →
Adecreases / increases
Bdecreases / unchanged
Cincreases / increases
Dincreases / unchanged
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14May / June 2024 · Paper 11 · Q15Show mark scheme →
Aice in an ice cube
Bwater in a lake
Cair in an air bubble
Dwater vapour in the atmosphere
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15May / June 2024 · Paper 11 · Q16Show mark scheme →
AThey move further apart and their average speed decreases.
BThey move further apart and their average speed increases.
CThey move further apart and their average speed remains unchanged.
DThey stay the same distance apart and their average speed decreases.
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16May / June 2024 · Paper 11 · Q17Show mark scheme →
A50 / 10
B100 / 50
C400 / 25
D400 / 100
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17May / June 2024 · Paper 12 · Q19Show mark scheme →
Abrown gas on the right and colourless gas on the left
Bpale brown gas throughout
Cseveral distinct clouds of colourless and brown gas throughout
Dcolourless gas on the right and brown gas on the left
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18Oct / Nov 2023 · Paper 11 · Q14Show mark scheme →
A100 kPa
B150 kPa
C200 kPa
D400 kPa
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19Oct / Nov 2023 · Paper 12 · Q18Show mark scheme →
AEach particle gets bigger and they collide with each other more often.
BEach particle gets bigger and they collide harder with the cylinder.
CThe particles gain kinetic energy and hit the cylinder harder and more often.
DThe particles lose kinetic energy and they hit the cylinder harder and more often.
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20Oct / Nov 2023 · Paper 12 · Q19Show mark scheme →
A0.40 p
B0.60 p
C1.5 p
D2.5 p
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21May / June 2023 · Paper 11 · Q15Show mark scheme →
Astronger / greater
Bstronger / smaller
Cweaker / greater
Dweaker / smaller
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22May / June 2023 · Paper 12 · Q15Show mark scheme →
AAfter the pressure is doubled, gas starts leaking into the cylinder.
BAfter the pressure is doubled, gas starts leaking out of the cylinder.
CThe temperature of the gas is constant.
DThe temperature of the gas is increasing.
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23Oct / Nov 2022 · Paper 11 · Q14Show mark scheme →
AP against 1/V graph
BP against V graph
CP against V graph (curve)
DP against 1/V graph (curve)
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24Oct / Nov 2022 · Paper 12 · Q15Show mark scheme →
A\frac{p_1 V_1}{V_2} + p_1
Bp_1 + \frac{p_1 V_2}{V_1}
C\frac{p_1 V_1}{V_2} - p_1
D\frac{p_1 V_2}{V_1} - p_1
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25Oct / Nov 2022 · Paper 12 · Q21Show mark scheme →
Amass of air: does not change; pressure of air: does not change
Bmass of air: does not change; pressure of air: changes
Cmass of air: changes; pressure of air: does not change
Dmass of air: changes; pressure of air: changes
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26May / June 2022 · Paper 11 · Q7Show mark scheme →
APressure is measured in N / m3.
BPressure multiplied by volume is a constant.
CPressure is directly proportional to 1/volume.
DThe ratio of V1 to V2 is equal to the ratio of p2 to p1.
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27May / June 2022 · Paper 11 · Q18Show mark scheme →
Aregular, strong
Bregular, weak
Cirregular, strong
Dirregular, weak
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28Oct / Nov 2021 · Paper 11 · Q15Show mark scheme →
Adecreases / decreases
Bdecreases / increases
Cincreases / decreases
Dstays the same / decreases
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29Oct / Nov 2021 · Paper 12 · Q11Also set in Oct / Nov 2021 Paper 11Show mark scheme →
A\frac{p}{2}
B\frac{p}{3}
C2p
D3p
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30May / June 2021 · Paper 11 · Q10Show mark scheme →
Ahalves
Bno change
Cdoubles
Dtriples
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31May / June 2021 · Paper 12 · Q14Show mark scheme →
Agraph A
Bgraph B
Cgraph C
Dgraph D
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32May / June 2021 · Paper 12 · Q22Show mark scheme →
Afixed / not regular
Bfixed / regular
Ctakes shape of container / not regular
Dtakes shape of container / regular
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33May / June 2021 · Paper 12 · Q23Show mark scheme →
AThe molecules expand and push on the container with a greater force.
BThe molecules move at the same speed and hit the container with a greater force.
CThe molecules move faster and hit the container more often.
DThe molecules move further apart and hit the container more often.
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34Oct / Nov 2020 · Paper 11 · Q5Show mark scheme →
Adensity
Bmass
Cpressure
Dvolume
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35Oct / Nov 2020 · Paper 11 · Q25Show mark scheme →
AAir molecules are much larger than Z.
BAir molecules are smaller than Z.
CAir molecules hit Z from different directions.
DAir molecules vibrate about a fixed position.
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36Oct / Nov 2020 · Paper 12 · Q12Show mark scheme →
A0.20 cm³
B0.60 cm³
C1.8 cm³
D2.4 cm³
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37Oct / Nov 2020 · Paper 12 · Q22Show mark scheme →
Apressure: decreases; reason: the molecules have less room to move in the cylinder
Bpressure: decreases; reason: the molecules move more slowly between collisions
Cpressure: increases; reason: the molecules collide more frequently with the piston
Dpressure: unchanged; reason: the temperature of the gas is constant
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38May / June 2020 · Paper 11 · Q25Show mark scheme →
Apressure decrease, temperature decrease
Bpressure decrease, temperature increase
Cpressure increase, temperature decrease
Dpressure increase, temperature increase
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39May / June 2020 · Paper 12 · Q15Show mark scheme →
A20 kPa
B25 kPa
C80 kPa
D100 kPa
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40May / June 2020 · Paper 12 · Q27Also set in May / June 2020 Paper 11Show mark scheme →
Alarge / free to move within the liquid
Blarge / vibrate at fixed positions
Csmall / free to move within the liquid
Dsmall / vibrate at fixed positions
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41May / June 2020 · Paper 12 · Q28Show mark scheme →
AThe molecules collide with the walls of the can more frequently when the air is heated.
BThe mass of the molecules is greater when the air is heated.
CThere are more molecules per unit volume when the air is heated.
DThe separation of molecules becomes greater when the air is heated.
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42Oct / Nov 2019 · Paper 12 · Q13Also set in Oct / Nov 2019 Paper 11Show mark scheme →
Agraph A: pressure against volume, straight line through origin
Bgraph B: pressure against volume, straight line decreasing from pressure axis
Cgraph C: pressure against volume, curve decreasing from pressure axis
Dgraph D: pressure against volume, curve increasing from origin
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43Oct / Nov 2019 · Paper 12 · Q20Show mark scheme →
Aaverage distance between air molecules: increases; density of the air: decreases
Baverage distance between air molecules: increases; density of the air: stays the same
Caverage distance between air molecules: stays the same; density of the air: decreases
Daverage distance between air molecules: stays the same; density of the air: stays the same
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44May / June 2019 · Paper 11 · Q21Show mark scheme →
AThey all have the same speed.
BThey are stationary.
CThey move at random.
DThey vibrate about a fixed point.
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45May / June 2019 · Paper 12 · Q15Show mark scheme →
Adensity: decreases; temperature: increases
Bdensity: increases; temperature: decreases
Cdensity: increases; temperature: remains constant
Ddensity: remains constant; temperature: increases
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46May / June 2019 · Paper 12 · Q23Show mark scheme →
AIt moves with changing speed and continuously changes direction.
BIt moves with changing speed in a straight line.
CIt moves with constant speed and continuously changes direction.
DIt moves with constant speed in a straight line.
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47May / June 2019 · Paper 12 · Q24Also set in May / June 2019 Paper 11Show mark scheme →
AThey expand.
BThey move faster inside the container.
CThey move further apart.
DThey vibrate with greater frequency.
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48Oct / Nov 2018 · Paper 12 · Q15Also set in Oct / Nov 2018 Paper 11Show mark scheme →
Ap/2
Bp/3
C2p
D3p
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49Oct / Nov 2018 · Paper 12 · Q18Also set in Oct / Nov 2018 Paper 11Show mark scheme →
AThey collide with the walls more often.
BThey contract.
CThey get closer together.
DThey move more slowly.
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50Oct / Nov 2018 · Paper 12 · Q20Also set in Oct / Nov 2018 Paper 11Show mark scheme →
Athe average kinetic energy of the molecules
Bthe molecular size
Cthe molecular spacing
Dthe total number of molecules
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51May / June 2018 · Paper 12 · Q18Show mark scheme →
AThe density of the air inside the packet increases.
BThe mass of the packet increases.
CThe pressure of the air outside the packet decreases.
DThe volume of the air inside the packet decreases.
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52May / June 2018 · Paper 12 · Q19Show mark scheme →
ATheir kinetic energy decreases.
BThey become heavier.
CThey expand.
DThey hit the container more frequently.
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53Oct / Nov 2017 · Paper 11 · Q11Show mark scheme →
AThey collide with the walls with less force.
BThey expand.
CThey move faster.
DThey move further apart.
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54Oct / Nov 2017 · Paper 12 · Q11Show mark scheme →
A72 cm3
B80 cm3
C720 cm3
D800 cm3
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55Oct / Nov 2017 · Paper 12 · Q12Show mark scheme →
AMolecules repel each other very strongly when very close.
BThe attractive forces between molecules are small at large distances.
CThe molecules in the gas collide with the walls of their container and rebound.
DThe molecules of a liquid are constantly moving at random.
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56May / June 2017 · Paper 11 · Q19Show mark scheme →
Apressure-volume graph: straight line through origin
Bpressure-volume graph: straight line decreasing to zero
Cpressure-volume graph: curve increasing from origin
Dpressure-volume graph: curve decreasing (inverse relationship)
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57May / June 2017 · Paper 12 · Q20Show mark scheme →
A$\dfrac{p_1}{V_1} = \dfrac{p_2}{V_2}$
B$\dfrac{p_1}{p_2} = \dfrac{V_1}{V_2}$
C$p_1 V_1 = p_2 V_2$
D$p_1 V_2 = p_2 V_1$
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58May / June 2017 · Paper 12 · Q21Also set in May / June 2017 Paper 11Show mark scheme →
Aa gas being heated
Ba liquid being heated
Ca liquid undergoing solidification
Da solid being heated
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59Oct / Nov 2016 · Paper 11 · Q14Show mark scheme →
Adecrease decrease
Bdecrease increase
Cincrease decrease
Dincrease increase
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60Oct / Nov 2016 · Paper 11 · Q15Show mark scheme →
AGas molecules collide with other gas molecules in the container.
BGas molecules collide with the walls of the container.
CGas molecules exert strong attractive forces on each other.
DGas molecules exert strong repulsive forces on each other.
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61Oct / Nov 2016 · Paper 12 · Q18Show mark scheme →
AThey move further apart and their average speed decreases.
BThey move further apart and their average speed increases.
CThey move further apart and their average speed remains unchanged.
DThey stay the same distance apart and their average speed decreases.
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62May / June 2016 · Paper 12 · Q12Also set in May / June 2016 Paper 11Show mark scheme →
A2.0 cm^3
B3.0 cm^3
C12 cm^3
D18 cm^3
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63May / June 2016 · Paper 12 · Q13Also set in May / June 2016 Paper 11Show mark scheme →
AThey collide less frequently.
BThey expand.
CThey move faster.
DThey move further apart.
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