IGCSE Chemistry 0620 Exam Format Explained

Cambridge IGCSE Chemistry 0620 is assessed through three components: one multiple-choice paper, one structured theory paper and one practical assessment. The route determines whether the candidate takes the Core or Extended multiple-choice and theory papers.

The current source of truth is the official Cambridge IGCSE Chemistry 0620 syllabus page. This guide is mapped to the 2026-2028 syllabus cycle.

Core and Extended routes

Core: Paper 1 + Paper 3 + Paper 5 or 6. Grades available: C to G.

Extended: Paper 2 + Paper 4 + Paper 5 or 6. Grades available: A to G*.

Extended candidates study the Core curriculum plus the Supplement. The Core vs Extended guide explains the decision and corrects the common misconception that Extended stops at grade E.

Every paper at a glance

Paper	Route	Format	Time	Marks	Weighting
Paper 1	Core	Multiple choice	45 minutes	40	30%
Paper 2	Extended	Multiple choice	45 minutes	40	30%
Paper 3	Core	Structured theory	1 hour 15 minutes	80	50%
Paper 4	Extended	Structured theory	1 hour 15 minutes	80	50%
Paper 5	Either route	Practical test	1 hour 15 minutes	40	20%
Paper 6	Either route	Alternative to Practical	1 hour	40	20%

A candidate takes one multiple-choice paper, one theory paper and one practical component.

Paper 1 and Paper 2: multiple choice

Both papers contain 40 questions in 45 minutes. Paper 1 assesses Core content. Paper 2 assesses Core plus Supplement.

This component tests more than rapid recall. Questions can require:

• selecting a correct definition or observation
• interpreting a diagram, graph or table
• completing a short calculation
• distinguishing between close distractors built from common errors
• applying Chemistry to a situation that is not copied directly from notes

There is no penalty for an incorrect answer, so every question should receive a response. A useful timing method is to answer secure questions first, mark longer calculations for review and reserve the final minutes for checked guesses rather than leaving blanks.

The dedicated Paper 2 multiple-choice guide covers distractor analysis, timing and error review for Extended candidates.

Paper 3 and Paper 4: structured theory

The theory component is worth 50% of the qualification. Paper 3 assesses Core. Paper 4 assesses Core plus Supplement.

Questions can combine several skills within one context:

• recall of definitions, formulae and observations
• balancing equations
• calculations with visible working
• explanations using particles, electrons, bonding, energy or equilibrium
• interpretation of unfamiliar data
• comparison and evaluation
• applying knowledge across more than one topic

The paper gives approximately 56 seconds per mark on average. That does not mean every one-mark item deserves exactly 56 seconds; it means a candidate cannot spend five minutes polishing a short response and still finish comfortably.

Use the mark allocation as a minimum structure. A three-mark explanation normally needs three creditable pieces of reasoning. A four-mark calculation should expose each stage so method marks remain available if the final arithmetic is wrong.

The Paper 4 theory guide provides a complete workflow for structured answers, calculations and unfamiliar contexts.

Paper 5: practical test

Paper 5 is completed in a laboratory. Candidates carry out experiments, record measurements, process results and draw conclusions.

Skills may include:

• reading apparatus accurately
• recording values to suitable precision
• constructing tables with headings and units
• plotting and interpreting graphs
• carrying out qualitative tests and recording observations
• identifying variables
• evaluating procedure and results
• suggesting realistic improvements

The marks are awarded for the quality of the experimental work and recording, not merely for reaching an expected final value. The Paper 5 practical guide explains the component in more detail.

Paper 6: Alternative to Practical

Paper 6 assesses practical and experimental skills in a written paper. Candidates do not carry out the experiment in the examination, but they must reason as someone who understands how the experiment works.

Common tasks include:

• reading apparatus diagrams and scales
• completing results tables
• plotting graphs and calculating gradients
• identifying anomalies
• planning an investigation
• selecting variables and control measures
• recording observations precisely
• identifying sources of error
• proposing specific improvements
• drawing conclusions from results

The Paper 6 guide is the main hub. It links to focused guides on planning investigations, tables and graphs, and errors and improvements.

Assessment objectives behind the papers

The syllabus assesses three broad objectives:

• AO1: knowledge and understanding
• AO2: handling information and problem-solving
• AO3: experimental skills and investigations

The qualification weighting is 50% AO1, 30% AO2 and 20% AO3. That is why reading notes alone is not a complete preparation method. Students must practise using information, solving problems and evaluating experiments.

What the weightings mean for revision

A balanced plan should reflect both the component weights and the student’s evidence.

• Theory deserves substantial time because it carries 50%.
• Multiple choice should be practised under time pressure and reviewed by error type.
• Practical skills deserve a deliberate weekly slot rather than being left until the mock.
• Weak high-frequency skills such as moles, equations, graph interpretation and observation language should be trained across papers rather than inside one topic only.

A student with a strong Paper 4 score but weak Paper 6 planning should not simply do more Paper 4. A student missing Paper 2 calculations needs targeted calculation review before another full paper.

Paper-specific answer habits

Multiple choice

• eliminate options using Chemistry, not intuition
• calculate before looking for a matching option where possible
• check units and powers of ten
• never leave a response blank

Theory

• identify the command word
• match points to marks
• show calculation stages and units
• use precise particles, forces, electron changes and observations
• answer the question asked rather than writing everything known about the topic

Practical assessment

• use headings and units in tables
• plot points accurately and use a sensible scale
• distinguish observations from conclusions
• identify a specific error and a matching improvement
• control variables that would otherwise change the result

Common format mistakes

1. Thinking Extended grades stop at E. Current 0620 Extended grades are A* to G.
2. Not knowing the entered paper numbers. Ask the school or examination centre.
3. Preparing only for the theory paper. The other two components account for half the qualification.
4. Using one revision method for all papers. MCQ elimination, structured writing and practical evaluation need different practice.
5. Ignoring the practical component until the mock. Graph, table and planning skills improve through repetition.
6. Treating marks as an approximate guide. The mark allocation indicates how many creditable points or stages are needed.

A sensible starting diagnosis

Use one recent paper from each component appropriate to the student’s route. Mark it carefully and classify every lost mark as:

• knowledge
• calculation
• application or data handling
• command-word or answer-language error
• practical skill
• timing or careless checking

That classification produces a useful plan. A raw overall percentage does not.

The site’s free diagnostic provides a topic-level starting point. A paid one-hour trial lesson can then examine a selected weak area with the assigned teacher before the family decides whether to continue.