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Learn Everything about G3 Science (Physics, Chemistry) in the MOE and SEAB Syllabuses | Understand SEC G3 Science Physics Chemistry

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by

eduKate Asia
Student with short hair in a blue pinafore smiles while holding a Science textbook.

Did you know the 2027 SEC G3 Science (Physics, Chemistry) qualification has a shared practical test and two separate structured papers? The subject code is K326. It is not the same examination as standalone Physics or Chemistry, even though the topics are related.

K326 candidates take 40 multiple-choice questions in Paper 1 (20%), Physics Paper 2 (32.5%), Chemistry Paper 3 (32.5%) and a 90-minute practical Paper 5 (15%). The combination makes conceptual understanding, numerical skills, experimental observations and balanced written explanations all important. This guide explains the actual paper numbering and how to build those skills.

The specifications follow the official SEAB 2027 G3 combined Science syllabus. All illustrative calculations, experiments and scenarios are original learning examples, not actual SEC examination questions. Practical work must be performed safely under school supervision.

Find the answer you need

Did you know G3 Science (Physics, Chemistry) has four examination papers?

The 2027 SEC subject is K326 Science (Physics, Chemistry), formerly 5086. It is one combined Science qualification using two disciplines, not separate standalone Physics K323 and Chemistry K324 entries. The official scheme requires Paper 1, Physics Paper 2, Chemistry Paper 3 and shared Practical Paper 5.

This distinction matters because the standalone subjects each have a different three-paper 30/50/20 assessment and broader or differently organised content. The combined K326 papers cover the subject’s own syllabus. Before revising, make sure the school record and question bank both identify K326, not just the words “G3 Science”.

Do you know the exact 20–32.5–32.5–15 weighting?

Paper 1 is a 60-minute multiple-choice paper carrying 40 marks and 20% of the grade. Physics Paper 2 lasts 75 minutes, carries 65 marks and contributes 32.5%. Chemistry Paper 3 also lasts 75 minutes, has 65 marks and contributes 32.5%. Paper 5 is a 90-minute practical test with 30 marks and 15%.

All four are compulsory for K326. Students cannot replace Chemistry Paper 3 with Biology Paper 4, because that belongs to another registered subject. Paper 1 and the practical assess both Physics and Chemistry. The two 65-mark discipline papers make detailed written explanations particularly significant.

Did you know Paper 1 is a shared examination across the three G3 combined-science codes?

The SEC scheme uses a one-hour, 40-question multiple-choice paper, covering the two appropriate science sections approximately equally. K326 includes Physics and Chemistry questions, K327 Physics and Biology, and K328 Chemistry and Biology. The same paper slot applies, but the tested content follows the registered combination.

For K326, the paper supplies the Periodic Table and the data sheet on colours of common metal hydroxides. These help with relevant Chemistry questions but do not replace understanding chemical tests or patterns. Students should practise selecting appropriate information, not memorise every printed entry without purpose.

Do you know how Physics Paper 2 is organised?

Physics Paper 2 contains compulsory Section A worth 55 marks and Section B worth 10 marks. The final Section A question is worth ten marks. Section B presents two questions; the candidate chooses one. Every question in this paper concerns the Physics section of K326, not standalone Physics’s different paper specification.

A good timing strategy starts with the 75-minute total and the marks attached to each task. Read both optional questions before deciding, but do not spend so long choosing that compulsory work is rushed. Make the calculations, units and explanations visible enough for a marker to follow.

Did you know Chemistry Paper 3 has a similar structure but different skills?

Chemistry Paper 3 also has 55 compulsory Section A marks and a 10-mark Section B choice between two questions. It tests the Chemistry section of K326, which may require balanced equations, observations, mole reasoning, particle models and evidence from experimental or environmental contexts.

The Chemistry paper includes a Periodic Table and the metal-hydroxide colour sheet. These reference materials reduce some recall demands but do not solve the problem. For example, knowing an element’s relative atomic mass will not tell a student automatically which species limit a reaction or why an electrolysis product appears.

Did you know the 90-minute Paper 5 is a real practical examination?

Paper 5 consists of one or two compulsory practical questions on each of the two sciences. K326 candidates therefore prepare for both Physics and Chemistry apparatus, methods, observations and evaluation. They have 90 minutes for the entire practical, worth 15% of the combined subject grade.

The practical tests how students generate and use evidence. A candidate may be asked to suggest a modification or extension to a procedure without actually performing that extension; the syllabus allocates between 10% and 20% of practical marks to such a task when set. School-supervised laboratory practice remains essential.

Do you know why a modification is different from a conclusion?

A conclusion explains what the recorded observations support. A modification proposes how to improve, alter or extend the investigation, given a particular goal. If an experiment measures a relationship over a narrow range, an extension might investigate additional safely feasible values. That is not the same as declaring the results more reliable.

Students should state what would be changed, what would be measured and which conditions should be controlled. A good modification has a specific purpose and could produce interpretable new data. It does not rely on a generic statement such as “repeat everything to be more accurate”.

Did you know theory assesses almost as much reasoning as knowledge?

The combined G3 Science syllabus gives approximately equal theory weighting to knowledge with understanding and handling information/solving problems. About 20% of the theory marks are allocated to recall within the first category. This means success requires reading unfamiliar information and drawing justified conclusions as well as remembering concepts.

When reviewing an MCQ, ask why the right option is right and why a tempting wrong option fails. For structured questions, distinguish the provided evidence, the applied scientific principle and the conclusion. Completing many familiar worksheets does not automatically build skill with a new graph or apparatus.

Do you know the Physics content has six organising sections?

The K326 Physics component is organised into Measurement, Newtonian Mechanics, Thermal Physics, Waves, Electricity and Magnetism, and Radioactivity. It includes physical quantities, kinematics, forces, energy, particles, heat transfer, waves, light, circuits and nuclear change.

A child should understand the role of physical models: a force diagram represents interactions, a graph represents measured quantities, and a circuit diagram represents connections. None is simply a picture to copy. Ask what each representation predicts or explains and which assumptions make it valid.

Did you know quantities, units and instruments are examined together?

A number without a unit can be scientifically incomplete. The Physics section expects correct use of SI quantities, prefixes, suitable measuring devices and ideas of precision. A student who measures 250 mm but substitutes 250 m in a formula creates an error of three orders of magnitude.

Teach the learner to identify the quantity, convert units before calculation and review whether the result makes physical sense. The practical paper additionally requires selecting instruments suitable for the magnitude and accuracy needed. An expensive tool is not automatically the best tool for every measurement.

Do you know why distance and displacement lead to different answers?

Distance is the length of the path travelled, while displacement includes change in position and direction. Average speed uses distance over time; average velocity uses displacement over time. For a hypothetical student walking 20 metres east and then 20 metres west, the total distance is 40 metres but the net displacement is zero.

The distinction helps interpret motion and prevents incorrect use of formulas. Always read whether the question supplies a speed-time graph or displacement-time graph. The slope or area has a different meaning depending on which quantities are on the axes.

Did you know a graph’s shape has physical meaning?

A distance-time graph’s gradient relates to speed under the stated conditions. The area under a speed-time graph can give distance travelled for the one-direction motion considered in the syllabus. A flat distance-time segment indicates no change in distance during that interval, while a flat non-zero speed-time segment indicates constant speed.

Students often copy the same sentence about “a straight line means constant speed” without checking which graph it is. Ask them to label each axis and unit first. The physical interpretation should follow the graph’s quantities, not its visual resemblance to a remembered diagram.

Do you know why forces should be treated as interactions?

Forces include contact forces such as friction and tension and non-contact forces such as gravity and magnetic interactions. A resultant force helps determine changes in motion. A common misconception is that an object moving steadily must have a forward resultant force; constant velocity can occur with balanced forces.

For an illustrative object of 2 kg accelerating at 3 m/s² under appropriate conditions, the resultant force is F = ma = 6 N. That value is the net force, not necessarily the force from one push. Force diagrams should identify all relevant interactions.

Did you know mass, weight and density are different quantities?

Mass is expressed in kilograms, weight is a gravitational force in newtons, and density is mass per unit volume. Near Earth the syllabus uses a gravitational acceleration of approximately 10 m/s² for relevant problems. A 3 kg object therefore has approximate weight 30 N, not mass 30 N.

For an idealised material specimen of 200 g occupying 50 cm³, density is 4 g/cm³. Before comparing with another value, ensure compatible units. A child’s ability to explain why the quantities differ is more important than repeating three formulas without context.

Do you know why pressure and moments need the right distance or area?

Pressure relates force to contact area. Turning effects depend on force and perpendicular distance from a pivot. Both are examples where geometry affects a physical result. If a 10 N perpendicular force acts 0.2 m from a pivot, the moment is 2 N m.

Students should avoid multiplying by an arbitrary diagonal length when a perpendicular distance is required. A careful labelled sketch is often the quickest way to prevent the error. If a question concerns pressure, identify the actual relevant contact area instead of assuming the entire visible surface is loaded.

Did you know work, energy and power are connected but not identical?

Energy can be transferred between stores and processes; power describes the rate of energy transfer. If an illustrative appliance transfers 500 joules in 25 seconds, its average power is 20 watts. A different appliance may have greater power but lower total energy use if it operates for less time.

A student should say which quantity is being requested before choosing a relationship. Questions about efficiency require identifying useful output and the total input. “Energy was lost” should usually be refined to an explanation of how energy was transferred to less useful outputs, such as heating.

Do you know why the particle model helps explain thermal Physics?

Matter is represented through particles whose arrangement and motion relate to observed states and thermal behaviour. Heating and cooling can alter temperature or lead to changes of state. Learners need to explain what happens at particle level rather than assume that a liquid’s particles vanish when it evaporates.

Heat transfer by conduction, convection and radiation occurs through different physical processes. An accurate answer identifies which conditions allow each mechanism and how the process affects a system. A diagram should support the reasoning, not replace it.

Did you know waves transfer energy without net transport of matter?

The Waves section includes general wave properties, the electromagnetic spectrum and light. In an appropriate wave model, the disturbance propagates while medium particles oscillate about their positions. Frequency, wavelength and wave speed are related, with speed equal to frequency multiplied by wavelength.

For an illustrative wave of 4 Hz and wavelength 0.75 m, its speed is 3.0 m/s. That is an application under the stated conditions, not evidence that changing frequency always changes propagation speed in every medium. Identify which quantities the problem fixes.

Do you know why an electromagnetic spectrum question is not just ordering colours?

Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays occupy different frequency and wavelength ranges in the electromagnetic spectrum. Students should distinguish their characteristics, uses and relevant safety considerations without assuming every kind of radiation causes identical effects.

The Light topic also requires accurate ray interpretations for reflection and refraction as prescribed. A learner should draw the normal and distinguish it from the surface. The physical law and units should control the answer, even if a supplied sketch is not to scale.

Did you know a circuit diagram is a map of connections?

The Electricity and Magnetism section includes charge, current, potential difference, resistance, DC circuits, practical electricity and electromagnetism. A circuit drawing uses symbols to represent connectivity. It is not necessarily arranged like the physical apparatus on a laboratory bench.

Students should trace series and parallel branches before using relationships such as V = IR. In a simple resistor with 3 A current and 4 Ω resistance under appropriate conditions, the potential difference is 12 V. The calculation should match the actual circuit, not an assumed path through the drawing.

Do you know why practical electrical safety matters?

A theory problem may involve household electrical concepts, but classroom practical investigations should use appropriate approved equipment and follow school supervision. Mains electricity is not a safe home-revision experiment. A learner can study circuit diagrams, identify protective features and interpret meter readings without exposing themselves to hazardous voltages.

When practising exam answers, distinguish how a measuring instrument is connected from what it measures. An ammeter and a voltmeter are not interchangeable. A systematic circuit sketch is more reliable than trial-and-error wiring.

Did you know radioactivity is still part of combined Physics?

K326’s Physics section includes Radioactivity. Students should distinguish unstable nuclear changes from ordinary chemical reactions and understand relevant properties, uses, hazards and simple models such as half-life. These ideas do not disappear simply because the subject is combined with Chemistry.

An idealised half-life example begins at 80 counts of activity above background and falls to 40 after one half-life, then 20 after two. Actual counting measurements can fluctuate, and background correction matters when stated. One half-life does not mean every atom has decayed.

Do you know why Chemistry needs three connected levels of explanation?

The K326 Chemistry section is arranged into Matter—Structures and Properties, Chemical Reactions, and Chemistry in a Sustainable World. It asks students to link visible observations, submicroscopic particles and written symbols. A precipitate is visible evidence; an ionic equation explains which species participate; a structure model explains why a property can occur.

A memorised colour chart alone does not provide the complete explanation. Ask the learner to describe what was observed, what chemical process is proposed and which evidence supports it. This establishes a repeatable reasoning habit for unfamiliar questions.

Did you know that experimental Chemistry begins with selecting a method?

The syllabus covers laboratory measurements and separation or purification methods. Filtration, crystallisation, distillation and chromatography solve different problems because substances have different physical properties. A filter does not isolate dissolved salt from water by itself.

A useful hypothetical question presents a mixture and asks which property makes a separation method suitable. Students should explain the method, the expected observation and its limitations. Any actual work with chemicals and glassware belongs in a supervised laboratory.

Do you know why an atom is not the same as an ion?

Protons determine an element’s identity while electrons influence bonding and charge. An ion forms when an atom or group of atoms gains or loses electrons; it does not require changing the nucleus. Isotopes differ in their neutron number, not their proton number.

Students should be able to explain an ion’s charge and electron configuration using the Periodic Table. If the child can copy a dot-and-cross picture but cannot describe how the particles are arranged in an ionic lattice, they need a structure-level explanation rather than more drawing practice.

Did you know a chemical equation is a numerical model?

Balanced chemical equations preserve atoms and supply molar ratios for chemical calculations. For a simple illustrative reaction, 2Mg + O₂ → 2MgO shows the atom counts and stoichiometric relationships. Students must write the correct species before balancing; changing the formula of the product to make numbers work is not valid.

When using the mole concept, convert mass to moles, apply the ratio and return to the requested quantity. Be careful about limiting reactants and stated conditions. An answer with impressive arithmetic but an unbalanced starting equation can still be chemically wrong.

Do you know how acids and qualitative tests work together?

Acid-base chemistry and qualitative analysis test the ability to connect chemical properties with observations and identification. A gas that turns limewater milky under suitable conditions can support the inference that carbon dioxide was produced. The full identity of an unknown salt may require additional tests.

For practice, record the sample, added reagent, observed colour or precipitate and justified inference. Do not invent an observation because the textbook says a particular ion “should” be present. The printed reference notes should be used intelligently, with actual practical work supervised by a teacher.

Did you know electrolysis is part of K326 Chemistry?

Electrochemistry appears within Redox Chemistry, alongside oxidation-state and electron-transfer ideas. The products of molten and aqueous electrolysis can differ because the species present and selective discharge conditions differ. A suitable explanation names the electrolyte, electrodes, ions and expected reactions.

The Chemistry section also covers patterns in the Periodic Table, energetics and rates of reaction. All three connect back to particle arrangements and interactions. Ask the child to explain how evidence leads to a prediction rather than simply list products or trend directions.

Do you know why rate and amount of product are different?

A reaction rate describes how fast a change occurs; the total amount of product depends on the quantities and chemistry of the reactants. Two gas-evolution curves may reach the same final volume but have different initial gradients. The steeper curve indicates faster initial gas production under comparable conditions.

Students should describe what the graph shows before explaining possible causes such as temperature, concentration, surface area or catalysts. The graph alone may not reveal which factor changed. A clear separation of observation and mechanism makes the answer more rigorous.

Did you know Chemistry in a Sustainable World is examinable?

Organic Chemistry and Maintaining Air Quality connect fuels, carbon compounds, polymers and environmental considerations with chemical understanding. Learners should distinguish crude oil as a mixture from a pure substance, saturated from unsaturated hydrocarbons, and a specific pollutant from a broad description of poor air quality.

An evaluative answer might weigh why a polymer is useful in one application against potential waste and disposal consequences. It should identify the chemistry and the relevant evidence, not claim that every plastic or fuel has identical impacts. Sustainability decisions need realistic context and trade-offs.

Do you know how the combined practical can test two very different skills?

A Physics task might involve timing, length, force or electrical measurements; a Chemistry task might require careful observation, solution handling or interpretation of supplied chemical tests. Both assess collecting usable evidence, but the instruments, units and hazards differ.

Plan for rapid reading of instructions and accurate records. A Physics table should include measured quantities and units; a Chemistry observation should distinguish what is seen from what is inferred. Neither is improved by fabricating ideal results. Students need practical confidence in both disciplines, not just the preferred one.

Did you know experimental fairness is not always fixed by repeating?

Repeats help assess consistency when conditions are comparable. They do not necessarily correct a systematic measurement bias or a design that changes two variables at the same time. A valid improvement must address the particular weakness.

For example, if an investigation tests the effect of wire length on resistance, changing wire material simultaneously would confound the explanation. Holding material constant addresses validity. Repeated readings may separately help estimate measurement variation. These are two different repairs serving different purposes.

Do you know why paper mistakes should be recorded by type?

An error in a Physics force diagram differs from a chemical formula error or a practical data-table mistake. Grouping everything as “Science mistakes” leaves parents and students uncertain about what to practise. Track units, concept selection, graph interpretation, particle reasoning, equation balancing, experimental design and timing separately.

After each correction, use a new question that tests the same principle in a changed setting. Improvement is the ability to apply the method independently, not the ability to reproduce a highlighted answer from a familiar paper.

Did you know K326, K327 and K328 are not freely interchangeable?

K326 pairs Physics and Chemistry. K327 pairs Physics and Biology. K328 pairs Chemistry and Biology. Each combination specifies Paper 1, Practical Paper 5 and its two discipline-specific structured papers. The shared practical format does not mean candidates can choose any two disciplines on the examination day.

If school materials say only “G3 Science”, confirm which K-code and science pair they address. A student on K326 does not gain the correct Chemistry Paper 3 practice from a Biology Paper 4 worksheet, however valuable that worksheet might be for general learning.

Do you know how to organise an eight-week K326 repair cycle?

Weeks 1–2: diagnose Physics measurement, graphs, force reasoning and Chemistry atomic structure, bonding and equations. Weeks 3–4: practise energy, heat, Chemistry moles, acids and evidence-based testing. Weeks 5–6: cover waves, circuits, redox, organic applications and data-based explanations. Weeks 7–8: rehearse Paper 1, both 75-minute discipline papers and supervised combined practical investigations.

Adapt these activities to the school’s teaching sequence and the learner’s actual gaps. Study time should reflect both science components, not simply which one feels easier. Include short independent explanations, not only completion of answer sheets.

Do you know which parent FAQs matter most about K326?

Is the practical exam optional? No, Paper 5 is compulsory and contributes 15%. Does K326 use Chemistry Paper 4? No, Chemistry is Paper 3; Paper 4 is Biology for other combined-science entries. Are Physics and Chemistry separate SEC subjects here? No, K326 is one combined subject. Does Paper 1 use only one science? No, it includes both approximately equally.

Is K326 available to private candidates? It is on the published 2027 G3 private-candidate list, but individual eligibility and practical arrangements must be verified with SEAB. The worked scenarios above are educational examples, not national examination questions.

Official 2027 K326 syllabus and connected guides

Next action for parents: verify K326, review a Physics Paper 2 response, a Chemistry Paper 3 response and the teacher’s practical feedback. Diagnose whether the learner’s biggest gap is quantitative reasoning, chemical representation, scientific interpretation or experimental technique before increasing full-paper practice.