AQA GCSE Physics Physics Paper 1 (Higher), June 2023: Question 8

10 marks · Standard Demand difficulty · Short Answer

Explain the alpha particle scattering experiment, the development of the atomic model, and electron energy level transitions.

Practise this question

Question

Question text

08 Scientists developed new models of the atom as new particles were discovered.

08.1 Draw one line from each particle to the year it was discovered.

[2 marks]

Particle Year of discovery

Electron 1897

Neutron 1911

Nucleus 1920

Proton 26 1932

The nucleus was discovered using an alpha particle scattering experiment.

Alpha particles were directed at a sheet of gold foil.

Figure 8 shows the paths taken by seven alpha particles, A, B, C, D, E, F and G.

Figure 8

*0258.*2 Explain why alpha particle A takes the path shown in Figure 8.

[2 marks]

08.3 Explain why the path of alpha particle B is more tightly curved than the path of alpha

particle C.

[2 marks]

08.4 What can be deduced about the atom from the paths taken by alpha particles

D, E, F and G in Figure 8?

[1 mark]

Tick ( ) one box.

The atom contains a nucleus.

The atom contains protons, neutrons and electrons.

The atom is mostly empty space.

08.5 How is the Bohr model of the atom different from the nuclear model of the atom?

[1 mark]

08.6 Explain how an electron can move up and down between energy levels in an atom.

[2 marks]

Mark scheme

Show the mark scheme

Question 8

AO /

Question Answers Mark

Spec. Ref.

08.1 2 AO1

4.4.1.3

4 correct for 2 marks

2 or 3 correct for 1 mark

additional line from a box on the left negates the mark for that box

AO /

Question Answers Extra information Mark

Spec. Ref.

08.2 ‘it’ is alpha particle A AO1

both the alpha particles and the allow alpha particles and 1

(gold) nucleus have positive / protons have positive / same

same charge charge

AO3

so the alpha particle and the allow like charges repel 1 4.4.1.1

gold nucleus repel each other – HYSICS – – 4.2.5.1

ignore deflection (this refers to 4.2.5.2

the path taken not the force)

AO /

Spec. Ref.

08.3 particle B passes closer to the ‘it’ is particle B 1 AO3

nucleus 4.4.1.1

any mention of particle B 4.2.5.1

so experiences a stronger colliding with the nucleus scores 1 4.2.5.2

(repulsive) force zero

so experiences a stronger

electric field

AO /

Spec. Ref.

08.4 the atom is mostly empty space 1 AO3

4.4.1.3

AO /

Spec. Ref.

08.5 in the Bohr model the electrons allow energy levels or shells for 1 AO1

orbit (the nucleus) at specific specific distances 4.4.1.3

distances

(whereas in the nuclear model

the electrons can orbit at a

continuous range of distances) – HYSICS – –

AO /

Spec. Ref.

08.6 to move to a higher energy level allow absorbs energy by 1 AO1

an electron absorbs energy collision with another electron 4.4.1.1

from electromagnetic radiation allow EM radiation for

electromagnetic radiation

to move to a lower energy level 1

an electron emits energy in the

form of electromagnetic

radiation

if no other mark scored allow 1

mark for an electron changes

energy level by emitting or

absorbing electromagnetic 23

radiation

Total Question 8 10

How to answer it

Atomic Structure and the Alpha Scattering Experiment

What this question tests

This question assesses your recall of the history of atomic discovery, understanding of Rutherford's alpha particle scattering experiment, electrostatic repulsion forces, the Bohr model of electron energy levels, and radiation transitions.

Timeline of subatomic particle discoveries (electron, nucleus, proton, neutron).
Evidence provided by the alpha scattering experiment (charge and empty space).
Inverse relationship between distance to a charge and electrostatic force experienced.
Structure of the Bohr model (fixed shells / discrete energy levels).
Absorption and emission of EM radiation causing electron transitions.

Question 08.1 • 2 Marks

Discovery Timeline of Atomic Particles

Matching particles to their discovery year

✅ Correct Pairings

Particle / Feature	Year of Discovery
Electron	1897 (J.J. Thomson)
Nucleus	1911 (Rutherford)
Proton	1920 (Rutherford)
Neutron	1932 (James Chadwick)

Mark scheme: 4 correct = 2 marks; 2 or 3 correct = 1 mark; 0 or 1 correct = 0 marks.

❌ Common Errors & Traps

Drawing multiple lines: An extra line leaving any particle box negates the mark for that particle.
Mixing up proton and neutron: Chadwick discovered the uncharged neutron last (1932), long after Rutherford named the proton (1920).

Question 08.2 • 2 Marks

Repulsion of Alpha Particle A

Explaining large-angle deflection (scattering backwards)

✅ Model Answer

Both the alpha particle and the gold nucleus have a positive charge (or the same charge) [1 mark], so they repel each other [1 mark].

Mark 1: Both alpha particle and nucleus are positively charged.
Mark 2: Like charges repel.

🧠 Exam Technique

Name both interacting bodies: state clearly that the alpha particle is positive and the nucleus is positive.
Use the physical cause: repulsion or like charges repel . Simply writing "it deflects" repeats the question and scores no marks.

Question 08.3 • 2 Marks

Comparing Curved Trajectories (B vs C)

Why path B curves more sharply than path C

✅ Model Answer

Alpha particle B passes closer to the nucleus than C [1 mark].

Therefore, it experiences a stronger repulsive force (or is in a stronger electric field) [1 mark].

Mark 1: Particle B is closer to the nucleus.
Mark 2: Experiences a larger / stronger force.

❌ Critical Trap

Never say it hits or collides: The mark scheme explicitly states: "any mention of particle B colliding with the nucleus scores zero". The particles never make contact because electrostatic repulsion turns them around beforehand.

Question 08.4 • 1 Mark

Undeviated Paths (D, E, F, G)

Deductions from undeflected alpha particles

✅ Correct Deduction

☑ The atom is mostly empty space.

1 Mark: Exactly one box ticked.

💡 Rutherford's Key Conclusions

Most pass straight through: Atom is mostly empty space.
A small fraction deflected through large angles: Mass and positive charge are concentrated in a tiny central nucleus.

Question 08.5 • 1 Mark

Bohr Model vs Rutherford Nuclear Model

How Niels Bohr adapted the atomic model

✅ Model Answer

In the Bohr model, electrons orbit the nucleus at specific distances (or in fixed energy levels / shells), whereas in the nuclear model electrons could orbit at any continuous distance.

1 Mark: Mention of electrons orbiting at specific distances, fixed energy levels, or discrete shells.

🧠 Exam Technique

Examiners look for the keywords "specific distances", "shells", or "energy levels". Avoid just saying "Bohr added electrons" (electrons were already present in Thomson's and Rutherford's models).

Question 08.6 • 2 Marks

Transitions Between Energy Levels

How electrons move up and down energy levels

✅ Model Answer

Moving up (higher level): An electron absorbs energy from electromagnetic radiation [1 mark].

Moving down (lower level): An electron emits energy in the form of electromagnetic radiation [1 mark].

Mark 1: Absorbs EM radiation to move up.
Mark 2: Emits EM radiation to move down.

💡 Easy Memory Trick

IN = UP: Takes in energy (absorbs radiation) to jump outwards to a higher level.
OUT = DOWN: Gives out energy (emits radiation/photons) when dropping inwards to a lower level.

Topics

Physics · P4: Atomic Structure

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