Lower Secondary Science Syllabus Guide
Sec 1 and Sec 2: 16 topics, 5 themes, and the science choice before Sec 3
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Lower Secondary Science (Sec 1 & 2) in brief
Lower Secondary Science is one subject taken across Secondary 1 and Secondary 2. Under the MOE G2/G3 Lower Secondary Science syllabus (implemented from the 2021 Secondary One cohort, updated April 2024), it has 16 topics grouped under five themes: The Scientific Endeavour, Diversity, Models, Interactions and Systems. MOE states that these themes give students the foundation for biology, chemistry and physics at upper secondary. The syllabus does not split the topics into a Sec 1 list and a Sec 2 list, so each school sets its own order. There is no national exam in Sec 1 or Sec 2.
Reviewed by Theon Teo, Founder · Last reviewed: 3 October 2026
All 16 topics of the Lower Secondary Science syllabus
The table lists every topic by its official name and theme, in the order MOE gives them in the G2/G3 Lower Secondary Science syllabus (MOE, PDF). The same 16 topics apply to students taking science at G2 and at G3. The last column is our own reading of which upper secondary science each topic leads into. It is not an MOE label, but it helps when you read a Sec 2 report by discipline.
| No. | Theme | Topic (MOE name) | Leads into at Sec 3 |
|---|---|---|---|
| 1 | The Scientific Endeavour | The Scientific Endeavour | All three sciences (practical and inquiry skills) |
| 2 | Diversity | Exploring Diversity of Matter by its Physical Properties | Chemistry and Physics (density) |
| 3 | Diversity | Exploring Diversity of Matter by its Chemical Composition | Chemistry |
| 4 | Diversity | Exploring Diversity of Matter using Separation Techniques | Chemistry |
| 5 | Models | Ray Model of Light | Physics |
| 6 | Models | Model of Cells: the Basic Unit of Life | Biology |
| 7 | Models | Model of Matter: The Particulate Nature of Matter | Chemistry and Physics |
| 8 | Models | Model of Matter: Atoms and Molecules | Chemistry |
| 9 | Interactions | Application of Forces and Transfer of Energy | Physics |
| 10 | Interactions | Transfer of Heat Energy and its Effects | Physics |
| 11 | Interactions | Chemical Changes | Chemistry |
| 12 | Interactions | Interactions within Ecosystems | Biology |
| 13 | Systems | Electrical Systems | Physics |
| 14 | Systems | Human Digestive System | Biology |
| 15 | Systems | Transport Systems in Living Things | Biology |
| 16 | Systems | Human Sexual Reproductive System | Biology |
Source: MOE, Science Syllabus, Lower Secondary, General 2 Course and General 3 Course, implementation starting with the 2021 Secondary One cohort (updated April 2024). The five themes are the same themes used in the primary science syllabus, so a student moving up from PSLE Science meets a familiar frame with more depth.
Sec 1 and Sec 2 science: is there an official topic split?
No. The MOE syllabus presents the 16 topics as one course for the two years of lower secondary. The only mention of Secondary One in the document is the line saying which cohort the syllabus started with. Which topics are taught in Sec 1 and which in Sec 2 is decided by each school, so two students in different schools can be on different topics in the same term.
For parents, the useful document is your child's own school topic schedule (scheme of work). Any online list of "Sec 1 science topics" describes one school's or one textbook's order, not a national standard.
G2 vs G3 Lower Secondary Science: what changes
Under Full Subject-Based Banding, Lower Secondary Science is offered at G1, G2 and G3. G2 and G3 share one syllabus document and the same 16 topics. The difference is in the learning outcomes: outcomes marked with an asterisk are labelled "Optional for G2 Lower Secondary Science". G3 students are expected to cover them, while G2 students may not. Some examples from the syllabus:
- Exploring Diversity of Matter by its Physical Properties: strength, hardness and flexibility as properties, and finding the volume of irregular objects by displacement.
- Separation Techniques: reverse osmosis in desalination and in treating used water.
- Ray Model of Light: refraction (no angle calculations) and the dispersion of white light by a prism.
- Model of Cells: the significance of division of labour at the cell level.
- Particulate Nature of Matter: explaining melting and boiling using the particle model.
- Application of Forces and Transfer of Energy: investigating pressure with pressure = force / area, and work done as a transfer of energy.
- Chemical Changes: reactions of acids with metals and with carbonates, and chemical change caused by an electric current (for example electroplating).
- Electrical Systems: how series or parallel resistors and varying resistance affect current, and calculating the cost of electricity in kilowatt-hours.
Some content is left out at every level. For example, the syllabus uses word equations only (chemical equations are not required) and does not require the formula V = IR. G1 students follow a separate MOE G1 Lower Secondary Science syllabus.
How Lower Secondary Science is assessed
There is no national exam in Sec 1 or Sec 2. Assessment is set by the school. Besides written tests, the MOE syllabus suggests performance tasks such as practical work, projects, model-making and posters. End-of-year examinations are meant to cover a representative sample of the syllabus, so students need to connect ideas across the two years rather than revise topic by topic. Formats and weightings differ from school to school.
The end-of-Sec-2 choice: Pure or Combined Science
Science stays compulsory at upper secondary, but the form it takes is chosen before Sec 3. MOE says schools consider each student's learning progress when guiding subject choices (MOE, Full SBB curriculum), so Sec 1 and Sec 2 science results matter even without a national exam. The SEC G3 options listed by SEAB for 2027 are:
- Pure sciences, each a separate subject: Physics (K323), Chemistry (K324), Biology (K325).
- Combined Science, two sciences in one subject: Science (Physics, Chemistry) K326, Science (Physics, Biology) K327, Science (Chemistry, Biology) K328.
Our view, not an MOE rule: read the Sec 2 report by discipline using the table above. A student who is comfortable with light, forces and electricity but weak on cells and ecosystems is showing a pattern that matters for this choice. Entry requirements for later courses differ, so check the specific course before deciding.
Sec 1 and Sec 2 students will sit the SEC, not the O-Level
The last GCE O-Level exams run from October to November 2026. From 2027, Sec 4 students sit the Singapore-Cambridge Secondary Education Certificate (SEC), with each subject taken at G1, G2 or G3. G3 keeps the O-Level standard. Any student in Sec 3 or below in 2026, which includes every current Sec 1 and Sec 2 student, will sit the SEC. Our guide on how the SEC replaces the O-Level from 2027 explains what else changes.
Common Lower Secondary Science Struggles We Fix
Sec 1 and Sec 2 Science marks are lost to technique and vocabulary more than to concepts. The patterns we see most often:
Answers use everyday language where the mark scheme expects scientific keywords (dissolving vs melting, mass vs weight, heat vs temperature).
Data-response questions on unfamiliar experiments are skipped or answered without referencing the data given.
The first calculations (density, and at G3 pressure and electricity cost) are treated like maths questions, with no units or wrong units.
Separation-technique questions are memorised as names rather than matched to the property each technique exploits.
Diagram answers (cells, digestive system, ray diagrams) are partially labelled or drawn without a ruler where lines are expected.
Revision starts days before a school test because "there is no big exam this year", and gaps build quietly into Sec 2.
These are the gaps our lower secondary science tutors work on with school-aligned topical work and weekly keyword and data-response practice, ahead of the Sec 3 subject choice.
Lower Secondary Science Programme Structure
A programme aligned to the five themes of the MOE Lower Secondary Science syllabus, sequenced to each school’s scheme of work:
The Scientific Endeavour and Diversity
The practice of science plus the three Diversity topics.
- Laboratory safety, apparatus and measurement
- Physical properties of matter, density and classification
- Elements, compounds and mixtures (diversity by chemical composition)
- Separation techniques (magnetic attraction, filtration, evaporation, distillation, paper chromatography)
- Matching each separation technique to the property it uses
Models (light, cells, matter)
The four model-based topics, where diagram discipline is first taught.
- Ray model of light (reflection, refraction, ray diagrams)
- Model of cells (plant and animal cell structures)
- Particulate nature of matter (states of matter, diffusion, expansion)
- Atoms and molecules
- Using models to explain observations, and their limitations
Interactions (forces, energy, heat, chemistry, ecology)
The four Interactions topics and the bridge into upper-secondary sciences.
- Application of forces and transfer of energy (types of forces, turning effects, pressure, work and energy)
- Transfer of heat energy and its effects (conduction, convection, radiation, expansion)
- Chemical changes (acids, alkalis, indicators, word equations)
- Interactions within ecosystems (food chains, food webs, human impact)
- Preview of Sec 3 Pure and Combined Science expectations
Systems (electrical and human body)
The four Systems topics.
- Electrical systems (current, potential difference, resistance, circuit diagrams)
- Human digestive system
- Transport systems in living things (including xylem and phloem in plants)
- Human sexual reproductive system
- Diagram labelling conventions for biology and circuit questions
Why parents pick us
School-Scheme Alignment
Lower secondary schemes of work differ school to school. We sequence lessons to your child’s school topic order and test calendar, not a generic national order.
Keyword Discipline From Day One
Scientific vocabulary habits start forming in Sec 1. We practise precise scientific phrasing before wrong habits set in.
Sec 3 Pathway Guidance
We explain how Sec 1 and Sec 2 progress feeds the Sec 3 subject combination, and advise honestly on the Pure vs Combined choice when it arrives.
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Lower Secondary Science (Sec 1 & 2): frequently asked questions
What topics are in the lower secondary science syllabus?
The MOE G2/G3 Lower Secondary Science syllabus has 16 topics under five themes. The Scientific Endeavour. Diversity: physical properties, chemical composition and separation techniques. Models: ray model of light, cells, the particulate nature of matter, and atoms and molecules. Interactions: forces and energy, heat, chemical changes and ecosystems. Systems: electrical systems, the human digestive system, transport systems in living things and the human sexual reproductive system.
What is in the Sec 1 science syllabus?
MOE does not publish a separate Sec 1 list. The syllabus covers all 16 topics across Sec 1 and Sec 2 as one course, and each school decides the order. Ask your child's school for its topic schedule to see which topics fall in Sec 1.
Is there a national exam for lower secondary science?
No. Sec 1 and Sec 2 science is assessed by the school, through written tests, practical and other performance tasks, and end-of-year examinations. The first national science exam is the SEC at the end of upper secondary.
What is the difference between G2 and G3 lower secondary science?
G2 and G3 use the same MOE syllabus and the same 16 topics. Learning outcomes marked with an asterisk are optional for G2, so G3 covers extra depth, for example refraction and dispersion of light, the pressure formula, acids with metals and carbonates, and the cost of electricity in kilowatt-hours. G1 has its own syllabus.
When do students choose between Pure and Combined Science?
Before Sec 3, at the end of Sec 2. Pure sciences are separate subjects (SEC G3 Physics K323, Chemistry K324, Biology K325). Combined Science examines two sciences in one subject (K326, K327 or K328). Schools consider each student's learning progress when guiding the choice.
Will my Sec 1 or Sec 2 child take the O-Level?
No. The last GCE O-Level is in 2026. Students in Sec 3 or below in 2026 sit the Singapore-Cambridge Secondary Education Certificate (SEC) from 2027, where G3 keeps the O-Level standard.
Lower Secondary Science (Sec 1 & 2) tuition: rates and tutors
Hourly rates by tutor tier and how lessons run for Lower Secondary Science (Sec 1 & 2).
See Lower Secondary Science (Sec 1 & 2) tuition →Official syllabus: MOE, G2/G3 Lower Secondary Science syllabus (PDF) · MOE, G1 Lower Secondary Science syllabus (PDF) · SEAB, SEC G3 syllabuses 2027
The Sec 3 Science Choice is Built in Sec 1 and 2
Schools look at learning progress when guiding the Pure or Combined Science choice before Sec 3, and that progress is built across Sec 1 and Sec 2.