Mark Scheme

Section A — Structured Questions (48 marks)

Question 1

(a) State what is meant by the term acceleration. (2 marks)

• Acceleration is the rate of change of velocity / change in velocity per unit time (1)
• Accept: change in speed per unit time if no direction change mentioned (1)

(b) Calculate the average speed of the trolley. (1 mark)

• average speed = (0 + 2.8) / 2 = 1.4 m/s (1)
• Accept: 1.4 with or without unit

(c) Calculate the time taken. (2 marks)

• time = distance / average speed (1)
• time = 2.0 / 1.4 = 1.43 s OR 1.4 s (1)
• Award 2 marks for correct answer without working

(d) Suggest how this change affects the time taken. Explain your answer. (2 marks)

• Time taken decreases / trolley takes less time (1)
• Because acceleration is greater / component of weight down slope is greater / resultant force is greater (1)
• Accept: steeper slope means faster motion

Question 2

(a) Calculate the weight of the girder. (2 marks)

• weight = mass × gravitational field strength / W = mg (1)
• W = 450 × 10 = 4500 N (1)
• Award 2 marks for correct answer 4500 N without working

(b) State the size of the upward force. (1 mark)

• 4500 N (1)
• Accept: equal to weight / same as weight
• Reject: 4500 without unit if not already given

(c)(i) Calculate the work done. (2 marks)

• work done = force × distance / W = Fd (1)
• W = 4500 × 12 = 54 000 J OR 54 kJ (1)
• Award 2 marks for correct answer without working

(c)(ii) Calculate the power output. (2 marks)

• power = work done / time OR P = W / t (1)
• time = 12 / 0.5 = 24 s, then P = 54 000 / 24 = 2250 W OR 2.25 kW (1)
• Accept: P = force × velocity = 4500 × 0.5 = 2250 W for full marks

(d) Explain why actual power input must be greater. (2 marks)

• Energy is wasted / lost (1)
• As heat / thermal energy OR due to friction OR due to inefficiency OR some energy is not transferred usefully (1)
• Accept: efficiency is less than 100%

Question 3

(a) Calculate the total resistance. (1 mark)

• 12 Ω / 12 ohms (1)
• Accept: R_total = 8.0 + 4.0 = 12.0 Ω

(b) Calculate the current. (2 marks)

• I = V / R (1)
• I = 6.0 / 12 = 0.5 A (1)
• Award 2 marks for correct answer without working

(c) Calculate the reading on the voltmeter. (2 marks)

• V = I × R (1)
• V = 0.5 × 8.0 = 4.0 V (1)
• Accept: ratio method 8/(8+4) × 6 = 4 V for full marks

(d) Explain why R₁ becomes hot. (3 marks)

• Current / charges / electrons flow through the resistor (1)
• Charges / electrons collide with atoms / lattice / ions in the resistor (1)
• Electrical energy is transferred to thermal / heat energy (1)
• Accept: energy is transferred from charges to the resistor
• Reject: "electricity" or "current" heats the resistor without mechanism

Question 4

(a)(i) Draw the reflected ray. (1 mark)

• Reflected ray shown at equal angle on opposite side of normal (1)
• Ray must have arrow showing direction away from mirror

(a)(ii) State the angle of reflection. (1 mark)

• 35° (1)

(b) Describe an experiment to verify the law of reflection. (4 marks)

Measurements (2 marks available):

• Direct ray from ray box at mirror / use single ray (1)
• Measure angle of incidence using protractor (1)
• Measure angle of reflection using protractor (1)
• Maximum 2 marks for measurements

Using the measurements (2 marks available):

• Repeat for different angles of incidence (1)
• Compare angle of incidence with angle of reflection / show they are equal (1)
• Accept: plot graph of angle of incidence vs angle of reflection and show it is a straight line through origin
• Accept: mark positions of incident and reflected rays, draw normal, measure angles

Maximum 4 marks total

(c) Explain why you can see your reflection in a mirror but not in white paper. (2 marks)

• Mirror reflects light regularly / specularly (1)
• Paper reflects light diffusely / scatters light in all directions / paper has rough surface (1)
• Accept: mirror is smooth and paper is rough
• Reject: mirror reflects light and paper does not

Question 5

(a) State the temperature change in kelvin. (1 mark)

• 80 K (1)
• Accept: 80 (unit not essential as same numerical value)
• Reject: 80°C

(b) Calculate the energy required. (3 marks)

• E = m × c × Δθ (1)
• E = 0.50 × 4200 × 80 (1)
• E = 168 000 J OR 168 kJ (1)
• Award 3 marks for correct answer without working
• Award 2 marks for correct substitution with calculation error

(c)(i) Describe what is happening to the water. (1 mark)

• Water is boiling / changing state / evaporating / turning to steam / changing to gas (1)
• Reject: "heating" or "getting hot" alone

(c)(ii) Explain why temperature does not increase. (2 marks)

• Energy is being used to overcome forces between molecules / break bonds (1)
• Not used to increase kinetic energy (of molecules) / used to increase potential energy (1)
• Accept: latent heat is being supplied
• Accept: energy changes state but not temperature

Question 6

(a) Complete the table. (3 marks)

Alpha nature: helium nucleus / 2 protons and 2 neutrons / particle (1) Beta stopped by: aluminium / few mm of aluminium / thin metal (1) Gamma stopped by: thick lead / several cm of lead / concrete (1)

Accept: α = helium atom without electrons Reject: "helium" alone for alpha Reject: "metal" alone for beta (must specify type or thickness)

(b)(i) State what is meant by half-life. (2 marks)

• Time taken for (number of) unstable nuclei / radioactivity / activity / count rate to halve (1)
• OR time taken for count rate to fall to half its initial value (1)
• Reject: "radiation" to halve
• Reject: "atoms" to halve unless "radioactive atoms" or "unstable atoms" specified

(b)(ii) Calculate the count rate after 18 hours. (2 marks)

• Number of half-lives = 18 / 6 = 3 (1)
• Count rate = 800 / 2³ = 800 / 8 = 100 counts per minute (1)
• Accept: 800 → 400 → 200 → 100 shown for both marks
• Award 2 marks for correct answer without working

(c) Explain why sources used in hospitals should have short half-lives. (2 marks)

• (Short half-life means) activity / radioactivity decreases quickly (1)
• Reduces (long term) harm / damage to patient / healthy tissue OR reduces radiation dose OR patient doesn't remain radioactive for long (1)
• Accept: source doesn't stay active in body for long time
• Reject: "safer" without explanation

Section B — Extended Response (32 marks)

Question 7 — Evaluate advantages and disadvantages of diesel vs electric trucks (15 marks)

Level 3 (11–15 marks): A comprehensive evaluation that includes accurate calculations of total costs and discusses multiple relevant physics concepts (energy efficiency, energy transfers, power). The response considers economic, practical, and environmental factors. A clear, justified recommendation is given based on the analysis. The answer is well-structured and uses correct scientific terminology throughout.

13–15 marks: All aspects of Level 3 with detailed discussion of at least 4 different factors. Calculations are complete and correct. Recommendation clearly follows from the analysis.

11–12 marks: Good coverage of Level 3 criteria but may lack some detail or have minor errors in calculations or reasoning.

Level 2 (6–10 marks): A competent response that includes some correct calculations and discusses some relevant physics concepts. Several factors are considered but the discussion lacks depth or contains some errors. An attempt at a recommendation is made but may not fully follow from the analysis. Scientific terminology is generally used correctly.

8–10 marks: Upper Level 2 – most calculations attempted correctly, discussion of 3-4 factors, reasonable conclusion.

6–7 marks: Lower Level 2 – calculations attempted with some errors, limited discussion of factors, weak conclusion.

Level 1 (1–5 marks): A basic response with simple or incorrect calculations. Limited discussion of relevant factors, possibly focusing only on cost or only on environmental issues. Little or no attempt at a justified recommendation. Limited use of scientific terminology or terms used incorrectly.

3–5 marks: Some relevant points and attempt at calculation.

1–2 marks: Minimal relevant physics content.

0 marks: No creditable content.

Indicative content (not exhaustive):

Calculations:

• Diesel: Total distance = 40 000 × 15 = 600 000 km
• Diesel: Energy cost = (600 000 / 100) × 18 = £108 000
• Diesel: Total cost = 45 000 + 108 000 = £153 000
• Electric: Energy cost = (600 000 / 100) × 6 = £36 000
• Electric: Total cost = 72 000 + 36 000 = £108 000
• Saving with electric = £45 000 over lifetime

Physics concepts:

• Energy efficiency: electric motors more efficient than diesel engines (typically 90% vs 40%)
• Energy transfer: diesel converts chemical to kinetic via thermal; electric converts electrical to kinetic with less waste
• Less energy wasted as heat in electric trucks
• Environmental: electric produces no emissions at point of use, but electricity generation may produce emissions
• Power considerations: both can provide adequate power for transport

Practical considerations:

• Electric has shorter range (400 km vs 800 km)
• Electric takes much longer to recharge (2 hours vs 5 minutes)
• May need more electric trucks or charging infrastructure
• Diesel more suitable for long-distance routes

Environmental:

• Diesel produces 180 g CO₂ per km; electric 0 g at point of use
• Total diesel emissions over lifetime = 600 000 × 180 / 1000 = 108 000 kg CO₂
• However, electricity generation may produce emissions (depends on source)

Recommendation (example):

• For short urban routes: electric trucks are more economical and environmentally better
• For long-distance routes: diesel may be more practical due to range and refueling time
• Overall recommendation should be justified by candidate's analysis

Question 8 — Nuclear fission and power generation

(a) Describe the process of nuclear fission. (6 marks)

6 marks: Clear, comprehensive description including all key points with correct terminology and logical sequence.

4–5 marks: Good description covering most key points with generally correct terminology.

2–3 marks: Basic description with some correct points but missing key details or some errors.

1 mark: Minimal relevant content.

Marking points:

• Large / heavy / unstable nucleus (e.g., uranium-235 or plutonium-239) (1)
• Is hit by / absorbs a neutron (1)
• Nucleus splits / breaks apart into two (smaller) nuclei / daughter nuclei / fission fragments (1)
• Energy is released (1)
• (Two or three) more neutrons are released / emitted (1)
• These neutrons can go on to cause further fission / chain reaction continues (1)
• (For controlled chain reaction) control rods absorb excess neutrons (1)
• Maximum 6 marks

Accept: descriptions of how chain reaction is maintained or controlled for final marks Reject: nucleus "explodes" without mention of splitting Reject: "atom" throughout instead of "nucleus" – maximum 4 marks

(b) Discuss advantages and disadvantages of nuclear vs fossil fuel power stations. (11 marks)

Level 3 (9–11 marks): A balanced, detailed discussion covering multiple factors. Both advantages and disadvantages are discussed with good scientific understanding. Environmental, economic, and practical considerations are included. A clear conclusion is reached based on the evidence presented. Scientific terminology is used accurately throughout.

10–11 marks: Excellent discussion of at least 5 different factors with clear justification for conclusion.

9 marks: Good Level 3 criteria met but slightly less detailed.

Level 2 (5–8 marks): A reasonable discussion covering several factors. Some advantages and disadvantages are identified for both types of power station. Discussion shows some scientific understanding but may lack depth or contain minor errors. An attempt at conclusion is made. Scientific terminology is generally used correctly.

7–8 marks: Upper Level 2 – discussion of 4-5 factors, reasonable balance, some depth.

5–6 marks: Lower Level 2 – discussion of 2-3 factors, some imbalance or limited depth.

Level 1 (1–4 marks): A limited discussion with few factors considered. May be unbalanced (only advantages or only disadvantages). Scientific understanding is basic or contains significant errors. Conclusion is weak or absent. Limited use of scientific terminology.

3–4 marks: Some relevant points about 2-3 factors.

1–2 marks: Minimal relevant content.

0 marks: No creditable content.

Indicative content (not exhaustive):

Energy output and efficiency:

• Nuclear fuel contains much more energy per kg than fossil fuels
• Small amount of nuclear fuel produces large amount of energy
• Both types have similar efficiency in converting thermal to electrical energy (around 35-40%)
• Nuclear power stations can operate continuously at high capacity
• Fossil fuel plants can be started/stopped more easily (flexibility)

Environmental impact:

• Nuclear produces no CO₂ / greenhouse gases during operation
• Fossil fuels produce large amounts of CO₂ contributing to climate change / global warming
• Nuclear produces radioactive waste (see below)
• Fossil fuel plants produce air pollution (sulfur dioxide, nitrogen oxides, particulates)
• Nuclear has very small fuel volume so less mining impact
• Fossil fuels require continuous mining/extraction with environmental damage

Fuel availability:

• Fossil fuels are running out / non-renewable (though still decades of supply)
• Uranium is also non-renewable but supplies will last longer
• Nuclear fuel is energy-dense so less fuel needed

Safety concerns:

• Nuclear accidents are rare but can be catastrophic (Chernobyl, Fukushima)
• Fossil fuel plants have good safety record
• Nuclear requires extensive safety systems and procedures
• Coal mining can be dangerous
• Radiation risk from nuclear plants

Waste disposal:

• Nuclear waste remains radioactive for thousands of years
• Difficult and expensive to store nuclear waste safely
• No permanent solution for high-level nuclear waste yet
• Fossil fuel waste (CO₂) goes into atmosphere
• Ash from coal contains some radioactive materials

Economic factors:

• Nuclear plants very expensive to build
• Nuclear plants expensive to decommission
• Nuclear fuel costs relatively low
• Fossil fuel prices vary but generally increasing
• Nuclear has high initial cost but low running cost

Conclusion (candidates may support either position if justified): Example supporting nuclear: reduces CO₂ emissions, reliable baseload power, fuel supply secure Example supporting fossil fuels: lower risk, no long-term waste problem, more flexible operation Example balanced: use both – nuclear for baseload, fossil fuels for peak demand (though renewable energy is better long-term solution)

Sample Answers with Examiner Commentary

Question 7 — Sample Answers

Grade A (high distinction) answer*

Calculations:

For diesel trucks over 15 years:

• Total distance = 40,000 km/year × 15 years = 600,000 km
• Energy cost = 600,000 ÷ 100 × £18 = £108,000
• Total cost = £45,000 + £108,000 = £153,000

For electric trucks over 15 years:

• Energy cost = 600,000 ÷ 100 × £6 = £36,000
• Total cost = £72,000 + £36,000 = £108,000

The electric truck is £45,000 cheaper over its lifetime despite the higher purchase cost.

Energy efficiency:

Electric trucks are significantly more efficient than diesel trucks. Electric motors typically convert about 90% of electrical energy into kinetic energy, whereas diesel engines only convert about 40% of the chemical energy in fuel into useful kinetic energy. The rest is wasted as heat and sound. This is why the running costs for electric trucks are only one third of diesel trucks – they need less energy input for the same work output.

Environmental impact:

Diesel trucks emit 180g of CO₂ per km. Over 600,000 km this equals 108,000 kg or 108 tonnes of CO₂, contributing significantly to climate change. Electric trucks produce 0g at point of use, which seems much better. However, we must consider that the electricity must be generated somewhere. If it comes from fossil fuel power stations, there will still be CO₂ emissions, though still less than diesel because of the higher efficiency. If the electricity comes from renewable sources like solar or wind, then the environmental advantage is much greater.

Practical considerations:

Diesel trucks have a major advantage in range (800 km vs 400 km) and refueling time (5 minutes vs 2 hours). For long-distance deliveries, a diesel truck could complete a journey that would require an electric truck to stop for a 2-hour recharge halfway through. This could mean needing more electric trucks and drivers to do the same work, adding extra costs not shown in the table. The company would also need to install charging infrastructure at their depot.

Recommendation:

For a delivery company doing mainly urban or short-distance routes (under 400 km per day), electric trucks are the better choice. They save £45,000 per truck over 15 years, are much better for the environment, and their shorter range and longer recharging time are not significant problems for this use. However, for long-distance routes, diesel trucks remain more practical. The ideal solution would be to use a mixed fleet: electric trucks for urban deliveries and diesel for long-distance routes, replacing the diesel trucks with electric as battery technology improves and charging infrastructure expands.

Mark: 15/15

Examiner commentary: This is an exemplary answer that achieves full marks. The calculations are complete, correct, and clearly presented. The response demonstrates excellent understanding of energy efficiency and energy transfers, using specific percentages and explaining why electric trucks are more efficient. The discussion is balanced, covering economic, environmental, and practical factors in depth. The environmental analysis shows sophisticated thinking by considering where electricity comes from. The recommendation is nuanced and well-justified, showing that the student can apply their analysis to real-world decision-making. Scientific terminology is used accurately throughout.

Grade C (pass) answer

Calculations:

Diesel trucks:

• Distance = 40,000 × 15 = 600,000 km
• Fuel cost = 600,000 ÷ 100 × 18 = £108,000
• Total = £45,000 + £108,000 = £153,000

Electric trucks:

• Electricity cost = 600,000 ÷ 100 × 6 = £36,000
• Total = £72,000 + £36,000 = £108,000

Electric is cheaper by £45,000.

Discussion:

Electric trucks are better because they are cheaper to run. The electric truck costs more to buy (£72,000 compared to £45,000) but the electricity is much cheaper than diesel. Over 15 years the electric truck saves £45,000 which is a lot of money.

Electric trucks are also better for the environment because they don't produce any carbon dioxide. Diesel trucks produce 180g per km which causes global warming. The electric trucks produce 0g so they are much cleaner.

Electric motors are more efficient than diesel engines so less energy is wasted. This means electric trucks need less energy to travel the same distance, which is why the running costs are lower.

However, diesel trucks can go 800 km on a full tank but electric trucks can only go 400 km. This means electric trucks would need to stop and recharge more often. Also recharging takes 2 hours compared to 5 minutes for diesel, so the trucks would be off the road for longer.

Recommendation:

I think electric trucks are better because they are cheaper and better for the environment. The company should choose electric trucks.

Mark: 9/15

Examiner commentary: This answer demonstrates good understanding and achieves a solid Grade C. The calculations are fully correct and clearly shown (4 marks secured). The student discusses several relevant factors including cost, environment, efficiency, and practical considerations. However, the discussion lacks the depth of a top answer: the efficiency section doesn't explain why electric motors are more efficient or give specific figures; the environmental section doesn't consider where electricity comes from; the practical limitations are identified but not fully explored (e.g., impact on fleet size or need for charging infrastructure). The recommendation follows logically but is somewhat simplistic. To reach the higher levels, the student needed to develop their points more fully and show more sophisticated analysis.

Grade E (near miss) answer

Electric trucks cost £72,000 and diesel cost £45,000 so diesel is cheaper.

Diesel trucks use £18 per 100 km and electric use £6 per 100 km. So electric is cheaper to run.

Electric trucks are better for the environment because they don't pollute. Diesel trucks produce carbon dioxide which is bad for the environment and causes global warming. Electric trucks produce no pollution so they are cleaner and better.

Diesel trucks can go further (800 km) than electric trucks (400 km) and they are quicker to refuel (5 minutes instead of 2 hours).

Electric trucks are more efficient because electricity is better than diesel.

I think the company should buy diesel trucks because they cost less money and can go further.

Mark: 5/15

Examiner commentary: This answer shows some relevant knowledge but lacks the calculations and depth needed for higher marks. The student has not calculated the total lifetime costs, which is a key requirement – they only compare purchase prices (missing up to 4 marks for calculations). The discussion identifies relevant factors (cost, environment, range, refueling) but with minimal development: the efficiency point is vague ("electricity is better than diesel") without explaining energy transfers or percentages; the environmental point doesn't consider the full picture of electricity generation. The recommendation contradicts their own evidence about running costs and shows limited ability to evaluate the data. To improve, the student needs to complete the required calculations, develop each point with more detail and scientific explanation, and ensure their conclusion follows logically from their analysis.

Question 8(b) — Sample Answers

Grade A (high distinction) answer*

Nuclear power stations have several significant advantages over fossil fuel power stations. The most important is that nuclear fission produces no carbon dioxide or greenhouse gases during operation, whereas burning fossil fuels releases large quantities of CO₂ which is the main cause of climate change and global warming. Given the urgent need to reduce greenhouse gas emissions, this is a major advantage. A single nuclear power station can replace several fossil fuel plants without contributing to climate change.

Nuclear fuel is also extremely energy-dense. One kilogram of uranium-235 can produce millions of times more energy than one kilogram of coal. This means that a very small amount of nuclear fuel can power a city for months or years, whereas fossil fuel plants require constant delivery of large quantities of coal, oil, or gas. Less fuel means less mining and transportation, reducing the environmental impact of fuel extraction. Nuclear power stations can also operate continuously for months between refueling, providing reliable baseload electricity supply, whereas fossil fuel supplies can be disrupted by political issues or price fluctuations.

However, nuclear power has serious disadvantages. The most significant is radioactive waste, particularly high-level waste which remains dangerously radioactive for thousands of years. There is currently no permanent solution for disposing of this waste safely – it must be stored in secure facilities and monitored indefinitely, leaving a dangerous legacy for future generations. Fossil fuel waste (mainly CO₂) is released into the atmosphere where it contributes to climate change, but it is not toxic or dangerous to handle like nuclear waste.

Safety is another major concern. Although nuclear accidents are rare, when they do occur they can be catastrophic. The Chernobyl disaster in 1986 released radioactive material across Europe, caused many deaths, and made a large area uninhabitable for decades. The Fukushima accident in 2011 also released radiation and forced the evacuation of over 100,000 people. Fossil fuel power stations have much better safety records and accidents affect only the immediate area. However, some argue that fossil fuel pollution causes far more deaths globally through air pollution and climate change impacts.

The economics also differ significantly. Nuclear power stations are extremely expensive to build (typically £10-20 billion for a modern plant) and take many years to construct. They are also very expensive to decommission safely at the end of their life. Fossil fuel plants cost much less to build and can be constructed more quickly. However, nuclear fuel costs are relatively low whereas fossil fuel prices have been increasing, so over the 60-year lifetime of a nuclear plant the total costs may be comparable.

Fossil fuel power stations have an advantage in flexibility – they can be started and stopped relatively quickly to match changing electricity demand throughout the day. Nuclear plants operate best at constant output and are difficult to adjust, so they provide baseload power but not peak power.

In conclusion, both types of power station have significant problems. Fossil fuels cause climate change which is an urgent global threat, while nuclear power creates radioactive waste and carries catastrophic accident risks. On balance, I believe we need to build more nuclear power stations in the short term because reducing CO₂ emissions is critical and nuclear is currently the only proven technology that can provide large-scale, reliable, low-carbon electricity. However, the long-term goal should be to replace both fossil fuel and nuclear power with renewable energy sources like wind and solar as these technologies improve and energy storage solutions develop.

Mark: 11/11

Examiner commentary: This is an outstanding answer that achieves full marks in Level 3. It provides a comprehensive, balanced discussion covering all the key factors: environmental impact (CO₂ vs radioactive waste), energy output and fuel availability, safety, economics, and operational characteristics. The student demonstrates sophisticated understanding by making comparisons throughout rather than just listing points separately, and by acknowledging counter-arguments (e.g., fossil fuel pollution causes more deaths than nuclear accidents). The environmental analysis is particularly strong, recognizing both the climate benefits of nuclear and the serious waste problem. The conclusion is well-reasoned and nuanced, supporting nuclear power while acknowledging it's not a perfect solution. Scientific terminology is used accurately and the answer is well-structured with clear paragraphs. This is the work of a candidate who can evaluate complex issues and reach justified conclusions.

Grade C (pass) answer

Advantages of nuclear power:

Nuclear power stations do not produce carbon dioxide when they are generating electricity. This is good because CO₂ causes global warming and climate change. Fossil fuel power stations produce lots of CO₂ when they burn coal, oil or gas, so they are bad for the environment.

Nuclear fuel contains a lot more energy than fossil fuels. A small amount of uranium can produce as much energy as a large amount of coal. This means you need less fuel and less mining.

Nuclear power stations can produce electricity all the time without stopping, giving reliable power. They don't run out of fuel quickly like fossil fuel stations that need constant deliveries.

Disadvantages of nuclear power:

Nuclear power produces radioactive waste which is very dangerous. This waste stays radioactive for thousands of years and has to be stored carefully. Nobody has found a good way to get rid of it permanently. Fossil fuel waste just goes into the air.

Nuclear power stations can have accidents that release radiation. Chernobyl was a very bad accident that killed people and made lots of land unusable. Fossil fuel power stations are safer and don't have accidents like this.

Nuclear power stations are very expensive to build. They cost billions of pounds and take many years to build. Fossil fuel power stations are cheaper and quicker to build.

Conclusion:

I think we should not build more nuclear power stations because they are too dangerous and the waste problem has not been solved. Even though they don't produce CO₂, the risk of accidents and the problem of radioactive waste make them too dangerous. Fossil fuel power stations are safer and we should use them until we can use renewable energy instead.

Mark: 7/11

Examiner commentary: This is a sound Grade C answer that covers the main points but lacks the depth and balance of a top-level response. The student has correctly identified key advantages (no CO₂, energy-dense fuel, reliable operation) and disadvantages (radioactive waste, accident risk, high cost), demonstrating good knowledge. However, the discussion is presented as separate lists rather than an integrated evaluation, and several points lack development (e.g., "fossil fuel waste just goes into the air" doesn't acknowledge this causes climate change; no mention of efficiency, fuel availability beyond basic points, or operational flexibility). The conclusion shows the student can reach a judgment but it's somewhat one-sided, not fully acknowledging the counter-argument about climate change being an urgent problem. To reach higher marks, the student needed to develop points more fully, make more comparisons between the two options, and produce a more balanced evaluation showing appreciation of the complexity of the issue.

Grade E (near miss) answer

Nuclear power stations split atoms to make electricity. They use nuclear fission. Fossil fuel power stations burn coal and gas.

Advantages of nuclear:

Nuclear power doesn't make pollution like fossil fuels. Fossil fuels make smoke and carbon dioxide which causes global warming. Nuclear is clean energy so it is better for the environment.

Nuclear fuel lasts a long time so you don't need much of it.

Disadvantages of nuclear:

Nuclear power is dangerous because of radiation. If there is an accident people can die from the radiation. Chernobyl was a nuclear accident that was very bad.

Nuclear waste is radioactive and dangerous. It has to be buried underground.

Nuclear power stations cost a lot of money.

Advantages of fossil fuels:

Fossil fuel power stations are cheaper than nuclear power stations.

They are safer because there is no radiation.

Conclusion:

I think fossil fuels are better because they are safer and cheaper. We should use fossil fuels.

Mark: 4/11

Examiner commentary: This answer demonstrates basic knowledge but remains in Level 1 due to limited development and significant weaknesses. The student has identified some relevant points (no CO₂ from nuclear, radiation danger, waste issues, cost differences) but nearly all points lack explanation or detail. Key errors include calling nuclear "clean energy" without acknowledging radioactive waste, and stating fossil fuels are "better" in the conclusion despite having just explained they cause global warming. Several important factors are missing entirely (energy density discussed properly, efficiency, fuel supplies, operational characteristics, the scale of the climate change problem). The structure is very basic with short, undeveloped points. To improve significantly, this student needs to explain each point more fully with scientific detail, discuss more factors, show understanding that this is a complex issue with no simple answer, and ensure their conclusion actually addresses the question of whether more nuclear power stations should be built in the context of climate change.