Cambridge IGCSE · Analysis & Prediction

2025 Cambridge IGCSE Science - Combined (0653) Past Paper: Analysis & Answers

An analysis of the October/November 2025 Cambridge IGCSE Combined Science (0653) papers 13, 23, 33, 43, and 63. This series presents a balanced assessment across Biology, Chemistry, and Physics, with emphasis on practical skills, unit conversions, and fundamental chemical bonding.

Updated: Jun 13, 2026

AnalysisSample paper
Difficulty 3.2/5
Total marks
160
Duration
180 mins
Most tested
—

Paper breakdown

Paper 2: Multiple Choice (Extended): 40 marks · 45 minsPaper 4: Theory (Extended): 80 marks · 75 minsPaper 6: Alternative to Practical: 40 marks · 60 mins

Examiner insights

Official report

Common pitfalls

  • Failing to convert time from minutes to seconds before substituting into the equation Q = It.
  • Using the wrong acceleration of free fall constant (or omitting it) during weight and force calculations (using m instead of mg).
  • Drawing non-linear axes or inconsistent scales on graph plotting questions in Paper 6.
  • Forgetting to write the charges on ions when completing structured ionic bonding diagrams.

Misconceptions

  • Believing that any organic molecule with carbon and hydrogen is a hydrocarbon, ignoring the presence of other atoms like oxygen or chlorine.
  • Confusing transpiration with evaporation generally, rather than defining it specifically as loss of water vapour from stomata.

Where marks are lost

  • In complete combustion equations, failing to balance oxygen diatomic molecules correctly.
  • Losing the final unit mark in calculations (such as density g/cm3 or resistance ohms).
  • Inability to link the rate of reaction to increased surface area / higher frequency of successful collisions in particle theory explanations.

Estimated grade boundary

Updated: Jun 13, 2026

Source: Cambridge IGCSE grade thresholds (official)
GradeMarkPercentage
A*150/20075%
A126/20063%
B102/20051%
C78/20039%
D68/20034%
E58/20029%
Official grade boundaries published by Cambridge IGCSE grade thresholds (official).

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