AQA GCSE Physics Physics Paper 1 (Foundation), June 2023: Question 2

8 marks · Low Demand difficulty · Short Answer

Answer questions on the development of atomic models, alpha particle scattering by a gold nucleus, and calculate the radius of a gold nucleus.

Practise this question

Question

Question 02 consists of seven parts about the history and models of the atom. Part 02.1 asks which subatomic particle was discovered first (Electron, Neutron, or Proton). Figure 3 shows three alpha particles (A, B, C) approaching a gold nucleus, with particle A getting closest and being deflected backward at a large angle, B deflected moderately, and C deflected slightly. Part 02.2 gives the radius of an alpha particle as 1.7 femtometres and states a gold nucleus is 4.2 times larger, asking for the radius of a gold nucleus. Parts 02.3 to 02.5 ask about charges, type of electrostatic force, and which particle experiences the largest force. Parts 02.6 and 02.7 provide Table 1 listing Bohr, Nuclear, Plum pudding, and Tiny spheres that cannot be divided, asking which model was developed first and which was developed last.
Question text

02 Scientists developed different models of the atom as new discoveries were made.

02.1 Which particle in the atom was discovered first?

[1 mark]

Tick ( ) one box.

Electron

Neutron

Proton 8

In an experiment that led to the nuclear model of the atom, alpha particles were

directed at a sheet of gold foil.

Figure 3 shows the path of three alpha particles passing close to a gold nucleus.

Figure 3

02.2 An alpha particle has a radius of 1.7 femtometres.

The radius of a gold nucleus is 4.2 times larger than the radius of an alpha particle.

Calculate the radius of a gold nucleus in femtometres.

[2 marks]

Radius of a gold nucleus =9 femtometres

02.3 Alpha particles are deflected by the gold nucleus.

What are the charges on an alpha particle and a gold nucleus?

[1 mark]

Tick ( ) one box.

An alpha particle and a gold nucleus are both neutral.

An alpha particle and a gold nucleus are both positively charged.

*08* An alpha particle is positively charged and a gold nucleus is neutral.

02.4 Which statement describes the force between the alpha particle and the

gold nucleus?

[1 mark]

Tick ( ) one box.

A contact force

A force of attraction

A force of repulsion

There is no force

02.5 Which alpha particle in Figure 3 experiences the largest force from the gold nucleus?

[1 mark]

Tick ( ) one box.

A B 10C

Table 1 lists different models of the atom in alphabetical order.

Table 1

Model

Bohr

Nuclear

Plum pudding

Tiny spheres that cannot be divided

02.6 Which model in Table 1 was developed first?

[1 mark]

02.7 Which model in Table 1 was developed last?

[1 mark]

Mark scheme

Show the mark scheme Mark scheme for Question 2: 02.1 requires 'electron' (1 mark). 02.2 awards 1 mark for radius = 1.7 × 4.2, and 1 mark for 7.14 femtometres (allow 7.1). 02.3 requires 'an alpha particle and a gold nucleus are both positively charged' (1 mark). 02.4 requires 'a force of repulsion' (1 mark). 02.5 requires 'A' (1 mark). 02.6 requires 'tiny spheres that can’t be divided' (1 mark). 02.7 requires 'Bohr' (1 mark). Total marks: 8.

Question 2

AO /

Question Answers Extra information Mark

Spec. Ref.

02.1 electron 1 AO1

4.4.1.3

AO /

Spec. Ref.

02.2 radius = 1.7 × 4.2 1 AO2

4.4.1.3

radius = 7.14 (femtometres) allow 7.1 (femtometres) 1

AO /

Spec. Ref.

02.3 an alpha particle and a gold 1 AO1

nucleus are both positively 4.4.1.1

charged 4.4.2.1

AO /

Spec. Ref.

02.4 a force of repulsion 1 AO1

4.2.5.1

4.2.5.2

AO /

Spec. Ref.

02.5 A 1 AO3

– HYSICS – – 4.2.5.2

AO /

Spec. Ref.

AO1

02.6 tiny spheres that can’t be 1 4.4.1.3

divided

AO / 9

Spec. Ref.

AO1

02.7 Bohr 1 4.4.1.3

Total Question 2 8

How to answer it

Atomic Structure: History & Alpha Particle Scattering

📋 What this question tests

This question assesses your recall of the chronological models of the atom, understanding of the Rutherford alpha particle scattering experiment, electrostatic forces between charged particles, and straightforward mathematical scaling of subatomic distances.

Question 02.1 • 1 Mark

First Subatomic Particle Discovered

Identifying the earliest discovered particle in the atom

✅ Correct Answer

Tick: Electron

Award 1 mark for selecting 'Electron'.

💡 Key Knowledge

  • Electron: Discovered in 1897 by J.J. Thomson (led to the Plum Pudding model).
  • Proton: Discovered later (Rutherford, around 1917–1920).
  • Neutron: Discovered last in 1932 by James Chadwick.
Question 02.2 • 2 Marks

Calculating Nuclear Radius

Multiplying atomic scale dimensions

📐 Step-by-Step Calculation

  1. Identify given values:
    Alpha radius = 1.7 femtometres
    Multiplier = 4.2
  2. Multiply to find gold nucleus radius:
    1.7 × 4.2 = 7.14 femtometres
[1 mark] for substitution 1.7 × 4.2
[1 mark] for final answer 7.14 (or 7.1 )

❌ Common Errors

  • Unnecessary unit conversions: Students often try to convert femtometres into metres ( ×10⁻¹⁵ ). The question already provides and asks for femtometres, so no unit conversion is needed.
  • Rounding errors: Rounding to 7 without showing working can risk marks; write 7.14 or round appropriately to 7.1 .
Question 02.3 • 1 Mark

Charges on the Particles

Charges of an alpha particle and a gold nucleus

✅ Correct Answer

Tick: An alpha particle and a gold nucleus are both positively charged.

Award 1 mark for the correct box.

💡 Key Knowledge

  • Alpha particle: Consists of 2 protons and 2 neutrons (helium-4 nucleus). Because it has 2 protons and no electrons, it has a +2 charge.
  • Gold nucleus: Contains protons and neutrons. Protons are positive and neutrons are neutral, making the entire nucleus positive.
Question 02.4 • 1 Mark

Nature of the Electrostatic Force

Identifying force type between like charges

✅ Correct Answer

Tick: A force of repulsion

Award 1 mark for selecting 'A force of repulsion'.

🧠 Exam Technique

Remember the fundamental rule of electrostatics: like charges repel, opposite charges attract. Since both the alpha particle (+) and nucleus (+) are positive, the force pushing them apart must be repulsion.

Question 02.5 • 1 Mark

Comparing Deflection and Force

Determining which particle experiences the greatest force

✅ Correct Answer

Tick: A

Award 1 mark for selecting 'A'.

💡 Key Knowledge & Explanation

  • Distance matters: Electrostatic force increases significantly as distance decreases.
  • Trajectory analysis: Particle A passes closest to the gold nucleus, so it experiences the strongest repulsive force and is deflected through the largest angle.
  • Particle C is farthest away, so it experiences the weakest force and suffers the least deflection.
Questions 02.6 & 02.7 • 2 Marks Total

Timeline of Atomic Models

Chronological development of atomic theory

✅ Correct Answers

02.6 (Developed First): Tiny spheres that cannot be divided

02.7 (Developed Last): Bohr

[1 mark] for 'tiny spheres that cannot be divided'
[1 mark] for 'Bohr'

💡 Timeline of Models (Oldest to Newest)

  1. Tiny spheres that cannot be divided: John Dalton (1803) - matter made of indivisible spheres.
  2. Plum pudding model: J.J. Thomson (1904) - ball of positive charge with embedded electrons.
  3. Nuclear model: Rutherford (1911) - mass and positive charge concentrated in a central nucleus.
  4. Bohr model: Niels Bohr (1913) - electrons orbit the nucleus at fixed distances (energy levels/shells).

❌ Common Errors

  • Confusing the Nuclear model with the Bohr model. Remember that Rutherford showed the nucleus exists, but Bohr adapted this by discovering distinct electron shells.
  • Writing names not listed in Table 1 (always copy directly from the options given in the prompt).

Topics

Physics · P4: Atomic Structure

Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Foundation), June 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.