How to Make Sense of the SEC G2 Science (Chemistry, Biology) Syllabus in Singapore

The SEC G2 Science (Chemistry, Biology) syllabus, code K225, is the official SEAB document for students in Singapore who study G2 Science through Chemistry and Biology, with no Physics. This guide explains the four K225 papers, what the Chemistry and Biology sections cover, what is printed in the papers and how to read the document with confidence.

What this quick-reference guide does: This K225 document reference gives a concise guide to Chemistry–Biology assessment arrangements. The primary guide provides original explanations of particles, reactions, cells, plant systems and responsible scientific conclusions. Match revision materials to the actual SEAB subject code, not merely to a broad Science or Mathematics label.

The K225 syllabus is official and exact.

It sits inside one G2 Science document, after a Physics section that K225 does not use.

It is easy to get lost before reaching the right pages.

With a little orientation, it becomes a practical map for revision.

This guide is useful for families who need to:

locate Papers 3, 4, 5 and 6 and see how they are timed;
list the nine Chemistry topics and eight Biology topics;
know what the syllabus says about the Periodic Table and practical work; or
read the assessment objectives without confusion.

At eduKateSG, lesson planning starts from the official syllabus, and this guide applies that habit to G2 Science.

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SEC G2 Science (Chemistry, Biology) Syllabus at a Glance

Syllabus code: K225
Subject code for reference (2026 and earlier): 5107, as shown on the SEAB listing page
Who it is for: school candidates taking G2 Science with Chemistry and Biology
Examination year of this document: 2027
The document: one combined G2 Science syllabus shared with K223 and K224
Papers: four, Papers 3 and 4 in Chemistry and Papers 5 and 6 in Biology
Total time: two sessions of 1 hour 15 minutes each
Weightings: Papers 3 and 5 are 20% each, Papers 4 and 6 are 30% each, so each science adds up to 50%
Practical: no practical paper; experimental skills are about 10% of the written-paper marks
Calculator: an approved calculator may be used in all papers
Periodic Table: a copy is printed as part of Papers 3 and 4
Formula sheet: not mentioned in the syllabus document
Where to download: SEAB 2027 SEC G2 syllabuses page

This guide is based on the SEAB syllabus document examined in 2027. SEAB can update syllabuses, so always check the latest version on the SEAB website.

What the Syllabus Is For

The three aims are shared across G2 Science. In plain words, the syllabus wants students to:

have a worthwhile experience of science, whether or not they continue with it;
understand and use the practices of science to solve real problems; and
grow values such as integrity, open-mindedness, resilience and healthy scepticism.

Both K225 sciences take the same stance in their introductions: less emphasis on factual material, more on understanding and applying concepts.

Chemistry asks what matter is and how particles interact. Biology asks how living organisms work to sustain life.

The document does not describe what comes before or after K225. SEAB lists it beside Science (Physics, Chemistry), K223, and Science (Physics, Biology), K224.

How the Examination Is Structured

Of the six papers in the combined document, K225 takes Papers 3, 4, 5 and 6. There are no Physics papers in K225.

Papers 3 and 4: Chemistry

Session: 1 hour 15 minutes, shared by both papers
Paper 3: Multiple Choice, 20 compulsory questions, 20 marks, 20%
Paper 4: Structured, 30 marks, 30%
Paper 4 Section A: 22 marks of compulsory structured questions, the last worth 8 marks
Paper 4 Section B: 8 marks, answer one of two structured questions
Periodic Table: a copy is printed as part of both papers

Papers 5 and 6: Biology

Session: 1 hour 15 minutes, shared by both papers
Paper 5: Multiple Choice, 20 compulsory questions, 20 marks, 20%
Paper 6: Structured, 30 marks, 30%
Paper 6 Section A: 22 marks of compulsory structured questions, the last worth 8 marks
Paper 6 Section B: 8 marks, answer one of two structured questions

The syllabus advises spending no more than 30 minutes on Paper 3 and on Paper 5. That leaves at least 45 minutes in each session for the structured paper.

Added up, the Chemistry papers and the Biology papers are worth 50% each.

What the Syllabus Covers

K225 uses the Chemistry and Biology sections: nine Chemistry topics and eight Biology topics, each science in three sections.

Chemistry I: Matter (Structures and Properties)

experimental chemistry;
the particulate nature of matter; and
chemical bonding and structure.

Chemistry II: Chemical Reactions

chemical calculations;
acid-base chemistry;
qualitative analysis; and
patterns in the Periodic Table.

Chemistry III: Chemistry in a Sustainable World

organic chemistry; and
maintaining air quality.

Biology I: Cells and the Chemistry of Life

cell structure and organisation;
movement of substances; and
biological molecules.

Biology II: The Human Body (Maintaining Life)

nutrition in humans;
transport in humans;
respiration in humans; and
infectious diseases in humans.

Biology III: Living Together (Plants and Animals)

nutrition and transport in flowering plants.

The pairing has natural links. Chemistry’s air-quality topic describes the carbon cycle, while Biology covers photosynthesis and respiration. Chemistry teaches tests for gases, and Biology’s practical list includes testing for carbon dioxide released during respiration.

What the Examiners Are Looking For

Chemistry and Biology papers are written to the same three assessment objectives.

Knowledge with Understanding: about 45%

Facts, concepts, vocabulary, apparatus and applications, with about 20% of the marks allocated to recall.

Handling Information and Solving Problems: about 45%

Organising information, translating it between forms, handling data, explaining patterns, predicting and solving problems.

Experimental Skills and Investigations: about 10%

Techniques, readings, interpreting data and improving methods, tested within the written papers.

Understanding and application carry real weight in both sciences.

How to Read the Syllabus Document

Start with the shared pages, pass over Physics, then read Chemistry and Biology closely.

Aims and Practices of Science: the purpose shared by all G2 Science combinations
Assessment Objectives: the three skill areas and their weightings
Scheme of Assessment: the K225 line, Papers 3, 4, 5 and 6
Physics Section: not part of K225
Chemistry Section: introduction, disciplinary ideas, content structure, subject content, key quantities, practical guidelines, Notes for Qualitative Analysis and the Periodic Table
Biology Section: introduction, disciplinary ideas, content structure, subject content, key quantities and practical guidelines
Glossary of Terms: command words such as “Classify”, “Compare” and “Suggest”
Special Note: nomenclature, including sulfur spelt with an f, plus units, significant figures and calculators

Common Misunderstandings

“K225 includes some Physics.”

It does not. K225 takes Papers 3, 4, 5 and 6 only, and the Physics papers belong to K223 and K224.

“There is a practical test.”

There is no practical paper. Students are expected to have carried out at least four tasks from each practical list, such as titration, identifying gases, using a light microscope and investigating enzymes.

“Every chemical calculation is examined.”

The syllabus sets limits. Stoichiometric calculations of reacting masses and volumes of gases are not required, and neither is calculating pH from hydrogen ion concentration.

“Everything needed is printed in the Chemistry papers.”

Only the Periodic Table is stated as printed, in Papers 3 and 4. The document does not mention a formula list, and it does not say the Notes for Qualitative Analysis appear in the papers.

“The two papers in a session are timed separately.”

Papers 3 and 4 share one 1 hour 15 minute session, as do Papers 5 and 6.

How Students Can Use the Syllabus

1. Go straight to your sections

Bookmark the Chemistry and Biology sections and the K225 line of the scheme of assessment.

2. Make a seventeen-topic tracker

List the nine Chemistry and eight Biology topics, and mark each as secure, shaky or new.

3. Get used to the Periodic Table

Practise reading it, since a copy is printed in both Chemistry papers.

4. Read the brackets

Notes such as “not required” mark the limits of a learning outcome.

5. Link practical work to theory

Theory papers may refer to the listed practical techniques, so know what each task is for.

6. Time each pair of papers

Keep each multiple-choice paper to 30 minutes or less in practice sessions.

How Parents Can Help

save or print the G2 Science document and mark the Chemistry and Biology sections;
ask your child to walk you through their topic tracker;
ask which practical tasks they have done in school;
check that your child has an approved calculator for the examination;
encourage steady revision of both sciences across the year; and
keep conversations about results calm and specific.

How eduKateSG Uses the G2 Science (Chemistry, Biology) Syllabus

we read the SEAB document directly, not second-hand summaries;
we help families find the K225 papers and pages within the combined document;
we use the stated limits in the learning outcomes to keep revision focused;
we use the assessment objectives to see whether a difficulty is about recall, handling information or experimental skills; and
we are honest about whether our classes are the right fit for a student’s science needs.

Getting Support

Every student starts from a different place.

Speak with us about your child’s level, subject and recent results. If our 3-pax classes are the right fit, we will explain how they work. If they are not, we will say so honestly.

Format: Premium 3-pax small-group tutorials, 1.5 hours weekly

The usual first step is a parent–student consultation.

What Parents Can Bring to the Consultation

Useful materials include:

a copy of the syllabus, or its code;
recent test papers and weighted assessments;
the latest report book;
the school’s assessment schedule; and
examples of questions the student finds difficult.

We are not only looking at the score.

We are looking for patterns.

Frequently Asked Questions

How many papers are there in SEC G2 Science (Chemistry, Biology)?

Four: Papers 3 and 4 in Chemistry and Papers 5 and 6 in Biology. Each pair is taken in one session of 1 hour 15 minutes.

How are the marks split between Chemistry and Biology?

Each science has a 20-mark multiple-choice paper worth 20% and a 30-mark structured paper worth 30%, so the two sciences are weighted equally.

Is the Periodic Table provided in K225?

Yes. A copy of the Periodic Table of Elements is printed as part of Paper 3 and Paper 4. An approved calculator may be used in all papers, and the document does not mention a formula sheet.

Is there a practical exam in K225?

No practical paper is listed in the scheme of assessment. Students are expected to have carried out at least four tasks from each practical list, and experimental skills are about 10% of the marks in the written papers.

Is K225 the same as the earlier syllabus 5107?

The SEAB listing page shows 5107 as the subject code for reference for 2026 and earlier. The K225 document does not describe any changes, so treat the 2027 PDF as your reference.

Where do I download the K225 syllabus?

From the SEAB page for 2027 SEC G2 syllabuses. It opens the combined G2 Science document, and K225 uses its Chemistry and Biology sections.

Helpful Reading

The eduKateSG Syllabus Series

Plain-language guides to SEAB syllabuses, from PSLE to A-Level. More guides are being added.

Science guides

PSLE Foundation Science (0039)
PSLE Science (0009)
SEC G1 Science (K123)
SEC G2 Science (Chemistry, Biology) (K225) (this guide)
SEC G2 Science (Physics, Biology) (K224)
SEC G2 Science (Physics, Chemistry) (K223)
SEC G3 Biology (K325)
SEC G3 Chemistry (K324)
SEC G3 Physics (K323)
SEC G3 Science (Chemistry, Biology) (K328)
SEC G3 Science (Physics, Biology) (K327)
SEC G3 Science (Physics, Chemistry) (K326)
A-Level H2 Biology (9477)
A-Level H2 Chemistry (9476)
A-Level H2 Physics (9478)

More Secondary (SEC) guides

SEC G2 Science (Chemistry, Biology) Syllabus: Matter and Life, Side by Side

The syllabus is not a textbook.

It is a map.

Two sciences. Seventeen topics. Four papers.

No Physics, and no practical paper.

The Periodic Table is printed in the Chemistry papers.

Read your two sections carefully, then revise a little at a time.

Arrange a Parent–Student Consultation

Speak with us about your child’s level, recent results, learning gaps and the dates ahead.

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How to Make Sense of the SEC G2 Science (Chemistry, Biology) Syllabus in Singapore | K225 Papers, Topics and Marks