0653 · Cambridge IGCSE
0653/61
Alternative to Practical
Science - Combined · June 2025 · Variant 1
Relative difficulty
Analysis source: Cambridge Assessment International Education
Analysis aligned to the official syllabus and assessment design.
3.4 / 5
160
180 min
Motion, forces and energy
Cohort performance
Session statistics from official examination reports
Total marks
160
Duration
180 min
Session difficulty
3.4 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
High-scoring candidates set themselves apart by mastering comparative questions and multi-step calculations.
In Biology, explaining the differences between active transport and diffusion requires explicit mention of concentration gradients and metabolic energy.
In Chemistry, the preparation of pure, dry crystals of copper nitrate serves as a classic four-mark procedural benchmark where candidates must clearly articulate the roles of filtration, evaporation, and slow crystallization.
In Physics, mechanics calculations involving kinetic energy Ek=12mv2 E_k = \frac{1}{2}mv^2 Ek=21mv2 and acceleration require strict attention to unit conversions—such as changing kilometers to meters—before applying formulas.
Question difficulty map
How candidates performed on each question in this series
No data available in official reports
Assessment objectives
Skill and AO weighting from official examiner commentary
Skill weighting
Shows the skill mix this paper tested most heavily.
Knowledge with
Weight: 4100%Handling Information
Weight: 375%Experimental
Weight: 125%
Method marks watchlist
Where working, steps, or method marks were commonly lost
No data available in official reports
Recurring mistakes across years
Themes examiners flag in multiple recent sessions for this subject
No data available in official reports
Question choice intelligence
Mean scores and popularity for optional questions (HKDSE electives)
No data available in official reports
Level exemplars
What candidate scripts at each grade level looked like
No data available in official reports
Grade & admission context
How marks relate to grade thresholds and entry standards
Report type
Cambridge Principal Examiner Report — component performance and international standards
Level A*
Approx. 72% of maximum mark
Level A
Approx. 61% of maximum mark
Level B
Approx. 49% of maximum mark
Level C
Approx. 38% of maximum mark
Level D
Approx. 33% of maximum mark
Level E
Approx. 28% of maximum mark
Deep insights
What top candidates did
Techniques and approaches examiners rewarded in this series
No data available in official reports
Command word playbook
How to match each command word to the expected response style
Match the expected response style for “State” questions.
Show formula, substitution, and unit; method marks need visible working.
Give reasons and link mechanism to outcome; each point needs a because/so chain.
State features in sequence or list observable properties — do not explain causes unless asked.
Match the expected response style for “Predict” questions.
Apply knowledge to an unfamiliar context; concise, practical points score best.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 1.5
Min per mark: 0.9
Syllabus traceability
Topics linked to questions and mark weighting in this session
Motion, forces and energy
13 marks this session
Electricity
11 marks this session
Transport in animals
9 marks this session
Reproduction
9 marks this session
Acids, bases and salts
9 marks this session
Atoms, elements and compounds
9 marks this session
MCQ trap analytics
Commonly chosen wrong options from examiner commentary
No data available in official reports
Topic heatmap across years
Mark concentration by topic and exam year for this subject
Mark intensity
Motion, forces and energy
Organic chemistry
Electrochemistry
Electricity
Motion, forces and energy (Physics)
Transport in animals
Reproduction
Acids, bases and salts
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
Paper 21 (Multiple Choice - Extended):
Paper 41 (Theory - Extended):
Paper 61 (Alternative to Practical):
Marks you can still earn
Where valid approaches outside the mark scheme may still gain credit
No data available in official reports
Practise what examiners flagged
Target weak topics from this report inside the Revui app
Motion, forces and energy
13 marks this session
Practise in RevuiElectricity
11 marks this session
Practise in RevuiTransport in animals
9 marks this session
Practise in RevuiReproduction
9 marks this session
Practise in RevuiAcids, bases and salts
9 marks this session
Practise in RevuiAtoms, elements and compounds
9 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
High-scoring candidates set themselves apart by mastering comparative questions and multi-step calculations.
- 2Message
In Biology, explaining the differences between active transport and diffusion requires explicit mention of concentration gradients and metabolic energy.
- 3Message
In Chemistry, the preparation of pure, dry crystals of copper nitrate serves as a classic four-mark procedural benchmark where candidates must clearly articulate the roles of filtration, evaporation, and slow crystallization.
- 4Message
In Physics, mechanics calculations involving kinetic energy Ek=12mv2 E_k = \frac{1}{2}mv^2 Ek=21mv2 and acceleration require strict attention to unit conversions—such as changing kilometers to meters—before applying formulas.
Teacher briefing pack
One-page session summary for tutors and classroom review
June 2025 2025
Science - Combined
High-scoring candidates set themselves apart by mastering comparative questions and multi-step calculations. In Biology, explaining the differences between active transport and diffusion requires explicit mention of concentration gradients and metabolic energy. In Chemistry, the
High-scoring candidates set themselves apart by mastering comparative questions and multi-step calculations.
In Biology, explaining the differences between active transport and diffusion requires explicit mention of concentration gradients and metabolic energy.
In Chemistry, the preparation of pure, dry crystals of copper nitrate serves as a classic four-mark procedural benchmark where candidates must clearly articulate the roles of filtration, evaporation, and slow crystallization.
- Total marks
- 160
- Duration
- 180 min
- Session difficulty
- 3.4 / 5
Session analysis
High-scoring candidates set themselves apart by mastering comparative questions and multi-step calculations. In Biology, explaining the differences between active transport and diffusion requires explicit mention of concentration gradients and metabolic energy. In Chemistry, the preparation of pure, dry crystals of copper nitrate serves as a classic four-mark procedural benchmark where candidates must clearly articulate the roles of filtration, evaporation, and slow crystallization. In Physics, mechanics calculations involving kinetic energy Ek=12mv2 E_k = \frac{1}{2}mv^2 Ek=21mv2 and acceleration require strict attention to unit conversions—such as changing kilometers to meters—before applying formulas.
Updated Jun 13, 2026
Paper breakdown
Paper 21 (Multiple Choice - Extended):
Paper 41 (Theory - Extended):
Paper 61 (Alternative to Practical):
Top chapters
Exam structure insights
Marks by chapter
See where the marks were concentrated so revision time goes to the highest-value topics.
Mark accessibility
Estimate which marks were basic, mid-level, or high-difficulty.
75% within easy or medium reach
Command word frequency
Spot common command words so answers match the expected response style.
Question type mix
Compare the mark share of each paper section and question type.
Structured Open
80·9·50%
Multiple Choice
40·40·25%
Practical/Planning
40·4·25%
Study ROI
Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.
Time vs marks
Compare marks with suggested time allocation to plan exam pacing.
Paper 21 (MCQ)
1.07 m/minPaper 41 (Theory)
0.67 m/minTotal marks
120
Total time
135 min
Avg pace
0.89
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Stoichiometry
90%90%
Space physics
85%85%
Examiner notes & key calculations
- Unit Vigilance: Examiners frequently note candidates failing to convert parameters to SI units, particularly in speed and energy equations. Always map out your units first.
- Precision in Definitions: In electricity, defining electromotive force (e.m.f.) requires using the exact terminology of work done per unit charge, rather than vague references to 'battery strength' or 'voltage'.
- Practical Graphing Accuracy: On Paper 51/61, ensure your line of best fit has an even distribution of points and is extended systematically to determine intercepts with the vertical axis.
Exam tips
Paper format
- Duration
- 1h
- Total marks
- 40
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.