AQA GCSE Physics 8463: Particle model of matter – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions cover section 4.3 Particle model of matter (4.3.1.1 to 4.3.3.3) of the AQA GCSE Physics (8463) specification, for teaching from September 2016 and exams from 2018 onwards. The topic is assessed on Paper 1, set at Foundation and Higher Tier. Part 11(b) tests content the specification marks (HT only) and is labelled Higher tier only; everything else suits both tiers. Questions 3 and 4 are based on required practical 5. Where a question needs ΔE = m c Δθ, E = m L or pV = constant, you would find these on the Physics equation sheet; ρ = m/V must be recalled.

Learn the content first in the Particle model of matter study guide and the revision notes. The course hub is AQA GCSE Physics, and the printable checklist lists every point.

Questions

1.

(a) Write down the equation that links density, mass and volume. [1] (b) A stone has a mass of 0.39 kg and a volume of 1.5 × 10⁻⁴ m³. Calculate its density. [2]

2. Describe the arrangement and motion of the particles in a liquid and in a gas, and use them to explain why a gas has a much lower density than the same substance as a liquid. [4]

3. A student wants to find the density of a small, irregularly shaped metal nut.

(a) Describe how she can measure the volume of the nut. [3] (b) The water level in her measuring cylinder rises from 40 cm³ to 54 cm³. The nut has a mass of 110.6 g. Calculate its density in kg/m³. [3]

4. An empty measuring cylinder has a mass of 85.0 g. With 60.0 cm³ of a liquid in it, the mass is 132.4 g. Calculate the density of the liquid in kg/m³. [3]

5.

(a) 50 g of ice melts completely. State the mass of water formed and explain why. [2] (b) State how a change of state differs from a chemical change. [1]

6.

(a) Define internal energy. [2] (b) Describe the two things that heating can do to a system, in terms of the energy of its particles. [2]

7. A heater transfers 27 000 J to a 1.5 kg aluminium block. Its temperature rises from 18 °C to 38 °C.

(a) Calculate the specific heat capacity of aluminium. [3] (b) The same energy is given to 1.5 kg of water (c = 4200 J/kg °C). Calculate the temperature rise. Give your answer to 2 significant figures. [2]

8. A 0.25 kg sample of a solid wax is heated by a 120 W heater. The temperature rises steadily to 62 °C at 150 s, stays at 62 °C until 800 s, then rises again. Assume all the energy from the heater goes to the wax.

(a) State the melting point of the wax. [1] (b) Explain why the temperature stays constant between 150 s and 800 s. [2] (c) Calculate the energy supplied between 150 s and 800 s. [2] (d) Calculate the specific latent heat of fusion of the wax. [2] (e) In reality some energy is lost to the surroundings. Suggest how this affects the value found in (d). [1]

9. A pan contains 0.80 kg of water at 30 °C. It is heated to 100 °C and then 0.10 kg of the water boils away. c = 4200 J/kg °C; specific latent heat of vaporisation = 2 260 000 J/kg.

(a) Calculate the total energy needed. [5] (b) Explain the difference between specific heat capacity and specific latent heat. [2]

10.

(a) Explain, in terms of molecules, how a gas exerts a pressure on the walls of its container. [2] (b) A sealed metal can of gas is heated. The volume stays the same. Explain why the pressure increases. [3] (c) A syringe holds 60 cm³ of air at 100 kPa. The plunger is pushed in slowly until the volume is 25 cm³. The temperature does not change. Calculate the new pressure. [3]

11.

(a) A cylinder holds a fixed mass of gas at 250 kPa in a volume of 0.012 m³. The gas is allowed to expand at constant temperature to 0.050 m³. Calculate its final pressure. [3] (b) Higher tier only. A cyclist pumps up a tyre quickly and the pump barrel becomes warm. Explain why. [3] (c) Use the particle model to explain why the pressure fell in (a). [2]

Answers

1. (a) density = mass ÷ volume (ρ = m / V) [1] (b) ρ = 0.39 ÷ 1.5 × 10⁻⁴ [1] = 2600 kg/m³ [1] Examiner insight: An answer with no unit, or with g/cm³ when the data are in kg and m³, loses the accuracy mark.

2. Liquid: particles touching but irregular, and able to move around each other [1]; gas: particles far apart, moving quickly and randomly [1]; in a gas the same mass takes up a much larger volume [1]; so the mass per unit volume (density) is much lower [1] Examiner insight: The explanation marks need the link from spacing to volume to density; “gas particles are lighter” is wrong and scores nothing.

3. (a) Part fill a measuring cylinder with water and read the volume [1]; lower the nut in fully submerged [1]; read the new volume; the increase is the volume of the nut [1] (b) V = 54 − 40 = 14 cm³ = 1.4 × 10⁻⁵ m³ [1]; ρ = 0.1106 ÷ 1.4 × 10⁻⁵ [1] = 7900 kg/m³ [1] Examiner insight: Giving 7.9 without converting to kg/m³ loses the final mark when the question asks for kg/m³, even though the working earns the method mark.

4. Mass of liquid = 132.4 − 85.0 = 47.4 g [1]; ρ = 47.4 ÷ 60.0 = 0.79 g/cm³ [1]; = 790 kg/m³ [1] Examiner insight: Dividing 132.4 by 60.0 uses the wrong mass and earns no marks, because subtracting the cylinder is the method step.

5. (a) 50 g [1]; mass is conserved because the number of particles stays the same, only their arrangement changes [1] (b) A change of state is physical: the material recovers its original properties if the change is reversed [1] Examiner insight: “Because it is the same substance” is too vague for the second mark in (a); say the particles are conserved.

6. (a) The total kinetic energy and potential energy [1] of all the particles (atoms and molecules) in the system [1] (b) It increases the kinetic energy of the particles, raising the temperature [1]; or it increases their potential energy, producing a change of state [1] Examiner insight: “Kinetic energy of the particles” alone earns only one mark in (a); both energies and “all the particles” are needed.

7. (a) Δθ = 38 − 18 = 20 °C [1]; c = 27 000 ÷ (1.5 × 20) [1] = 900 J/kg °C [1] (b) Δθ = 27 000 ÷ (1.5 × 4200) [1] = 4.3 °C [1] Examiner insight: Using 38 °C as Δθ is a method error, so the calculation earns no further credit.

8. (a) 62 °C [1] (b) The wax is changing state (melting) [1]; the energy increases the internal energy (potential energy of the particles), not the temperature [1] (c) t = 800 − 150 = 650 s; E = 120 × 650 [1] = 78 000 J [1] (d) L = E ÷ m = 78 000 ÷ 0.25 [1] = 312 000 J/kg [1] (e) The calculated value is too high, because not all of the 78 000 J went into melting the wax [1] Examiner insight: Error carried forward is allowed in (d): a wrong energy from (c) divided correctly by 0.25 kg still scores both marks.

9. (a) Heating: ΔE = 0.80 × 4200 × 70 [1] = 235 200 J [1]; boiling: E = 0.10 × 2 260 000 [1] = 226 000 J [1]; total = 461 200 J (≈ 461 000 J) [1] (b) Specific heat capacity is the energy to raise 1 kg by 1 °C, with no change of state [1]; specific latent heat is the energy to change the state of 1 kg with no change in temperature [1] Examiner insight: Using 0.80 kg in the boiling stage is a common method slip; only the 0.10 kg that changes state goes into E = m L.

10. (a) Molecules move randomly and collide with the walls [1]; each collision exerts a force on the wall, and force per unit area is pressure [1] (b) Heating increases the kinetic energy of the molecules, so they move faster [1]; they hit the walls more often [1]; and with more force, so the pressure increases [1] (c) p₁V₁ = p₂V₂: 100 × 60 = p₂ × 25 [1]; p₂ = 6000 ÷ 25 [1] = 240 kPa [1] Examiner insight: In (b), “more collisions” without “more often” (per second) or “harder” does not earn the marks.

11. (a) 250 × 0.012 = p₂ × 0.050 [1]; p₂ = 3.0 ÷ 0.050 [1] = 60 kPa [1] (b) Pushing the plunger does work on the gas, transferring energy to it [1]; this increases the internal energy of the gas [1]; so the average kinetic energy of the molecules, and the temperature, rise [1] (c) The molecules have more space, so they hit each unit area of wall less often [1]; their speed is the same at constant temperature, so the pressure is lower [1] Examiner insight: In (b), “friction in the pump” is not the physics being tested; the marks need work done on the gas and internal energy.

Where marks are usually lost

• Leaving volume in cm³ and mass in kg in the same density calculation.
• Using a final temperature in place of the temperature change.
• Using the total mass of water in E = m L when only part of it changes state.
• Forgetting to add the two stages of a heat-then-boil calculation.
• Describing a flat section of a heating graph as “no energy being supplied”.
• Defining internal energy without potential energy.
• Writing gas explanations with “more collisions” but no “per second” or “harder”.
• Applying pV = constant when the temperature changes, or mixing kPa with Pa between p₁ and p₂.

Next steps

• Recap with the Particle model of matter revision notes
• Relearn weak areas in the Particle model of matter study guide
• Course hub: AQA GCSE Physics
• Printable AQA GCSE Physics checklist
• Try all free 10-minute diagnostics
• Book a free trial class

Official syllabus

AQA GCSE Physics (8463) specification, for teaching from September 2016 onwards, for exams in 2018 onwards (Version 1.1, 30 September 2019), published by AQA. These questions cover section 4.3 Particle model of matter.