AQA GCSE Physics Physics Paper 1 (Higher), November 2021: Question 2

9 marks · Standard Demand difficulty · Short Answer

Answer questions on nuclear fusion, calculate the energy required to heat deuterium using specific heat capacity, and explain environmental impacts of fossil fuels.

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Question

Question text

02 Energy from the Sun is released by nuclear fusion.

02.1 Complete the sentences.

[2 marks]

Nuclear fusion is the joining together of .

During nuclear fusion the total mass of the particles .

02.2 Nuclear fusion of deuterium is difficult to achieve on Earth because of the high

temperature needed.

Electricity is used to increase the temperature of 4.0 g of deuterium by 50 000 000 °C.

specific heat capacity of deuterium = 5200 J/kg °C

Calculate the energy needed to increase the temperature of the deuterium

by 50 000 000 °C.

Use the Physics Equation Sheet.

[3 marks]

9 Energy = J

02.3 The idea of obtaining power from nuclear fusion was investigated using models.

The models were tested before starting to build the first commercial nuclear fusion

power station.

Suggest two reasons why models were tested.

[2 marks]

*08* 2

02.4 Generating electricity using nuclear fusion will have fewer environmental effects than

generating electricity using fossil fuels.

Explain one environmental effect of generating electricity using fossil fuels.

[2 marks]

Mark scheme

Show the mark scheme

Question 2

AO /

Question Answers Extra information Mark

Spec. Ref.

nuclei do not accept atoms 1

02.1 AO1

4.4.4.2

decreases 1

02.2 m = 0.004 (kg) 1 AO2

4.3.2.2

E = 0.004 × 5200 × 50 000 000 allow a correct substitution of an 1 4.1.1.3

incorrectly/not converted value

of m

E = 1.04 × 109 (J) allow a correct calculation using 1

or an incorrectly/not converted

E = 1 040 000 000 (J) value of m

02.3 any two from: 2 AO3

• to make sure the fusion 4.1.3

process is possible

• to develop an understanding

of the process

• to make adaptations to the

process

• to assess the efficiency of the

process

• to make predictions

• assess safety risks

• to assess environmental

impact

• set-up cost is lower (for small

scale experiments)

allow releases greenhouse

02.4 releases carbon dioxide 1 AO1

gases

4.1.3

which causes global warming allow which causes climate 1

change

releases particulates

which causes global dimming

which causes breathing

problems

releases sulfur dioxide

which causes acid rain

releases nitrogen oxides

which causes breathing

problems

which causes acid rain

Total 9

How to answer it

Nuclear Fusion, Thermal Energy & Fossil Fuel Impacts

Topic Overview

What this question tests

This question assesses key fundamental concepts across Particle Model of Matter, Atomic Structure, and Energy Resources:

Recall of nuclear fusion: Identifying that light nuclei join together and understanding mass loss in fusion.
Specific heat capacity calculations: Selecting the correct equation, converting mass units from grams to kilograms, and handling large values.
Working scientifically: Explaining why scale models are evaluated prior to large-scale engineering.
Environmental impacts: Explaining pollutant emissions from fossil fuels with their direct environmental consequences.

Part 02.1 • 2 Marks

Nuclear Fusion Sentence Completion

Completing the scientific definition and mass changes during fusion

✅ Correct Answers

First gap: nuclei [1 mark]
Second gap: decreases [1 mark]

Mark Scheme Note: Do not accept atoms for the first gap.

💡 Key Knowledge

Nuclear fusion happens at extreme temperatures and pressures where two smaller, lighter nuclei overcome electrostatic repulsion and fuse into a larger single nucleus. During this process, some of the mass is converted into energy (radiation), meaning the total mass of particles decreases.

❌ Common Errors

Writing "atoms": At fusion temperatures, electrons are stripped away, creating a plasma of bare nuclei. Saying "joining of atoms" scores 0.
Assuming mass is conserved: In nuclear reactions, a tiny amount of mass defect is released as immense energy via Einstein's mass-energy equivalence. Writing "stays the same" or "increases" loses the mark.

Part 02.2 • 3 Marks

Calculating Energy Needed for Heating Deuterium

Applying the Specific Heat Capacity equation with unit conversions

📐 Step-by-Step Calculation

Identify given data & check standard units:
Mass, m = 4.0 g ➔ Needs conversion to kg!
m = 4.0 / 1000 = 0.004 kg (or 4.0 × 10⁻³ kg ) [1 mark]
Specific heat capacity, c = 5200 J/kg °C
Temperature change, Δθ = 50 000 000 °C
Recall & substitute into the equation from sheet:
ΔE = m × c × Δθ
E = 0.004 × 5200 × 50 000 000 [1 mark]
Calculate the final answer:
E = 1 040 000 000 J or in standard form 1.04 × 10⁹ J [1 mark]

❌ Common Calculation Traps

Skipping mass conversion: Multiplying by 4.0 directly gives 1.04 × 10¹² J . This loses the first conversion mark (though error-carried-forward allows up to 2 marks).
Counting zeros incorrectly: Entering 50 000 000 (7 zeros) into a calculator can easily lead to a factor-of-ten mistake. Double check by using exponential mode ( 50 × 10⁶ or 5 × 10⁷ ).

🧠 Exam Technique

Always write out the converted value of mass explicitly on the page ( m = 0.004 kg ). Even if you make an arithmetic error later on your calculator, you will secure the conversion method mark!

Part 02.3 • 2 Marks

Why Scientists Test Scale Models

Suggesting two distinct reasons for building prototype models

✅ Mark Scheme Accepted Points (Any Two)

To make sure the fusion process is possible / feasible
To develop an understanding of the process
To make adaptations or improvements to the process
To assess the efficiency of the process
To make predictions
To assess safety risks
To assess environmental impact
Set-up cost is lower (cheaper to experiment at small scale)

🧠 How to Structure a 2-Mark "Suggest" Question

Make sure your two suggestions cover two separate categories (e.g., safety + cost, or feasibility + design tweaks):

Reason 1 (Practical/Economic): It is much cheaper to test and adapt a small prototype before spending billions on a full-scale plant.
Reason 2 (Safety/Feasibility): To evaluate safety hazards and prove that a sustained reaction is actually achievable under controlled conditions.

Part 02.4 • 2 Marks

Environmental Impacts of Fossil Fuels

Linking a specific emission to its direct environmental effect

🧠 The 2-Mark Cause & Effect Rule

An "explain" question worth 2 marks requires you to state WHAT is released (Cause, 1 mark) and WHAT it does to the environment (Effect, 1 mark). Never give a cause without its specific consequence!

✅ Pick ONE Pair for Full Marks

Pair 1: Releases carbon dioxide / greenhouse gases [1 mark] ➔ which causes global warming / climate change [1 mark]
Pair 2: Releases particulates [1 mark] ➔ which causes global dimming OR breathing problems / asthma [1 mark]
Pair 3: Releases sulfur dioxide [1 mark] ➔ which causes acid rain [1 mark]
Pair 4: Releases nitrogen oxides [1 mark] ➔ which causes acid rain OR breathing problems [1 mark]

❌ Common Errors to Avoid

Too vague: Saying "it causes pollution" or "destroys the environment" scores 0 marks.
Mismatched pollutants: Claiming carbon dioxide causes acid rain or sulfur dioxide causes global warming will deny both marks.
Ozone layer confusion: Carbon dioxide does not damage the ozone layer (CFCs do). Mentioning the ozone layer gets 0 marks.

Topics

Physics · P1: Energy · P3: Particle Model of Matter · P4: Atomic Structure

Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Higher), November 2021. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.