The 2026 Singapore Primary Science Frame

The current MOE Primary Science syllabus is built around Core Ideas, Practices, and Values, Ethics and Attitudes. Its Core Ideas are organised into five themes: Diversity, Cycles, Systems, Energy and Interactions. MOE also states that these themes should not be treated as sealed compartments; scientific ideas cross between them. That is exactly why vocabulary needs to be learned as a connected web rather than five unrelated word banks.

For the 2026 PSLE Science examination, SEAB assesses both knowledge with understanding and application of knowledge and scientific inquiry. Students are expected to interpret and analyse information, evaluate observations and methods, make predictions or hypotheses, and communicate explanations and reasoning. In other words, a keyword has value when it helps the student do scientific work.

Official references: MOE Primary Science Syllabus 2023 · SEAB 2026 PSLE Science 0009 Syllabus.

Why the Old “Memorise the Keyword” Method Breaks

Primary Science has a vocabulary problem, but it is not simply that children do not know enough words. Often the deeper problem is that the word is detached from the relationship it is supposed to carry.

• A student writes “friction” but does not say what two surfaces are interacting or how the motion changes.
• A student writes “photosynthesis” but does not connect light, carbon dioxide, water and food production in the plant.
• A student writes “evaporation” but cannot identify what gained enough energy to leave the liquid state.
• A student writes “circulatory system” but does not explain what is transported and where it must go.
• A student writes “fair test” but cannot identify the changed, measured and controlled variables.
• A student writes “evidence” but quotes a detail that does not actually support the conclusion.

This is why eduKatePunggol treats Science vocabulary as a precision-and-reasoning system. The term should help the student see a mechanism, distinguish two ideas, describe a pattern, identify evidence or communicate a causal relationship. If the word cannot do one of those jobs yet, it is not fully learned.

P3 → P6 | How the Vocabulary Load Changes

Stage	What the Science is asking the learner to do	Vocabulary emphasis
Primary 3	Notice differences, classify, describe materials, follow life cycles and reason about magnets.	Characteristic, classification, material, property, life cycle, stage, magnet, attract, repel.
Primary 4	Connect parts to functions, understand matter, light and heat, and begin reading systems.	System, part, function, root, stem, leaf, digestive system, solid, liquid, gas, reflection, heat, temperature.
Primary 5	Handle reproduction, the water cycle, plant transport, human respiratory/circulatory relationships and electrical systems.	Reproduction, pollination, germination, evaporation, condensation, transport, respiratory system, circulatory system, circuit, conductor, insulator.
Primary 6	Integrate photosynthesis, energy conversion, forces and environmental interactions; reconstruct unfamiliar situations.	Photosynthesis, energy conversion, frictional force, gravitational force, elastic spring force, food chain, producer, consumer, evidence, explanation.
PSLE	Retrieve the right concept, interpret evidence, choose the relevant relationship and express it precisely under examination conditions.	Command words and scientific-practice language become as important as topic nouns.

The progression matters. Primary 3 vocabulary is often concrete: what is it, what property does it have, where does it belong? By Primary 6, the child increasingly needs relational language: what changed, what caused the change, what evidence supports the claim, what is transported, what force acts, what happens next, and why?

The Canonical Top 100 | Learn the Word With Its Scientific Job

The list below is not a claim that every word is examined as an isolated definition. It is a teaching set: 100 high-value terms that help Primary students enter the current five-theme syllabus and the scientific practices used across questions. Each definition is deliberately short. The next step is always to use the word inside a relationship, diagram, investigation or explanation.

Diversity | 1–15

1. Living thing — an organism that carries out the characteristics of life.
2. Non-living thing — something that does not carry out the characteristics of life.
3. Characteristic — a feature used to describe, compare or classify something.
4. Classification — grouping things according to shared and differing characteristics.
5. Organism — an individual living thing.
6. Plant — a living organism studied for structures, functions, reproduction and energy relationships.
7. Animal — a living organism that obtains food from other organisms.
8. Material — the substance from which an object is made.
9. Property — a measurable or observable quality of a material.
10. Waterproof — does not allow water to pass through easily.
11. Absorbent — able to take in a liquid.
12. Transparent — allows most light to pass through so objects can be seen clearly.
13. Opaque — does not allow light to pass through.
14. Flexible — able to bend without breaking easily.
15. Magnetic material — a material attracted by a magnet.

Deepen this corridor: Top 100 Science “Diversity” Keywords →

Cycles | 16–31

16. Cycle — a sequence of stages or changes that repeats.
17. Life cycle — the stages through which a living thing develops and reproduces.
18. Stage — one distinguishable part of a cycle or process.
19. Reproduction — the process by which living things produce new individuals of their kind.
20. Pollination — transfer of pollen from anther to stigma in flowering plants.
21. Seed dispersal — movement of seeds away from the parent plant.
22. Germination — the beginning of growth of a seed under suitable conditions.
23. Matter — anything that has mass and occupies space.
24. Solid — matter with a fixed shape and fixed volume under ordinary conditions.
25. Liquid — matter with a fixed volume but no fixed shape.
26. Gas — matter with no fixed shape and no fixed volume.
27. Melting — change from solid to liquid.
28. Freezing — change from liquid to solid.
29. Evaporation — change from liquid to gas at the liquid surface.
30. Condensation — change from gas to liquid.
31. Water cycle — the continuous movement and change of water in the environment.

Deepen this corridor: Top 100 Science “Cycles” Keywords →

Systems | 32–53

32. System — a set of parts that interact to perform one or more functions.
33. Part — one component within a larger system.
34. Function — the job performed by a part or system.
35. Root — plant part that anchors the plant and absorbs water and mineral salts.
36. Stem — plant part that supports the plant and contains transport pathways.
37. Leaf — plant part that receives light and is a major site of photosynthesis.
38. Digestive system — organ system that breaks food down and allows useful substances to be absorbed.
39. Respiratory system — organ system involved in gas exchange.
40. Circulatory system — transport system that moves blood and carried substances around the body.
41. Heart — organ that pumps blood through the circulatory system.
42. Lungs — organs where gas exchange takes place.
43. Plant transport system — pathways that move water and food to different plant parts.
44. Water-carrying tube — plant transport structure that moves water from roots to other parts.
45. Food-carrying tube — plant transport structure that moves food from leaves to other parts.
46. Biological cell — a basic structural unit of living things.
47. Electrical system — connected electrical parts that allow electrical energy to be transferred and used.
48. Electric circuit — a complete path through which electric current can flow.
49. Electric cell — a source of electrical energy in a circuit.
50. Bulb — a component that converts electrical energy mainly into light and heat.
51. Switch — a component used to open or close an electrical circuit.
52. Conductor — material that allows electric current to pass through readily.
53. Insulator — material that does not allow electric current to pass through readily.

Deepen this corridor: Top 100 Science “Systems” Keywords →

Interactions | 54–68

54. Interaction — when one part of a situation affects another.
55. Force — a push or pull that can change motion or shape.
56. Magnet — an object that produces magnetic effects.
57. Magnetic force — force of attraction or repulsion associated with magnets.
58. Attract — pull towards.
59. Repel — push away.
60. Frictional force — force that opposes relative motion between touching surfaces.
61. Gravitational force — attractive force acting between masses; near Earth it pulls objects towards Earth.
62. Elastic spring force — force produced when a spring is stretched or compressed.
63. Environment — the surrounding living and non-living conditions affecting organisms.
64. Food chain — a sequence showing feeding relationships and transfer of energy.
65. Producer — an organism, typically a green plant, that makes its own food.
66. Consumer — an organism that obtains energy by feeding on other organisms.
67. Predator — an animal that hunts and feeds on other animals.
68. Prey — an animal hunted and eaten by a predator.

Deepen this corridor: Top 100 Science “Interactions” Keywords →

Energy | 69–80

69. Energy — a quantity transferred or converted when changes occur.
70. Energy form — a way energy is described in a situation, such as light or heat.
71. Energy source — something from which useful energy is obtained.
72. Energy conversion — change from one form of energy to another.
73. Light — energy that enables sight when it enters the eye.
74. Light source — an object that produces its own light.
75. Shadow — darker region formed when an opaque object blocks light.
76. Reflection — bouncing of light from a surface.
77. Heat — energy transferred because of a temperature difference.
78. Temperature — measure used to describe how hot or cold something is.
79. Heat transfer — movement of thermal energy from a hotter region to a colder region.
80. Photosynthesis — process by which green plants use light energy to make food from carbon dioxide and water.

Deepen this corridor: Top 100 Science Energy Keywords →

Scientific Practices | 81–100

81. Observation — information noticed or measured directly.
82. Inference — an interpretation made from observations and prior knowledge.
83. Prediction — a statement about what is likely to happen based on evidence or a pattern.
84. Hypothesis — a testable proposed explanation or relationship.
85. Variable — a factor that can change in an investigation.
86. Changed variable — the factor deliberately changed by the investigator.
87. Measured variable — the factor observed or measured as the outcome.
88. Controlled variable — a relevant factor kept the same so the comparison is meaningful.
89. Fair test — an investigation designed so the effect of the changed variable can be judged.
90. Experiment — a planned investigation used to collect evidence or test an idea.
91. Data — recorded observations or measurements.
92. Evidence — information used to support or challenge a claim.
93. Measurement — determining a quantity using an appropriate instrument and unit.
94. Unit — agreed standard used to express a measurement.
95. Pattern — a repeated or systematic relationship in observations or data.
96. Comparison — identifying meaningful similarities or differences using a common basis.
97. Conclusion — statement that answers the investigation question using the evidence collected.
98. Explanation — an account that connects evidence to scientific ideas and relationships.
99. Scientific model — a simplified representation used to describe, explain or predict a system or process.
100. Graph — a visual representation used to display relationships or patterns in data.

What a Keyword Must Be Able to Do in an Answer

There are at least six jobs a Science word may need to perform. Students should practise asking which job is required before inserting a keyword into an answer.

• Name: identify the correct part, process, force, system or property.
• Distinguish: show the difference between observation and inference, conductor and insulator, melting and freezing, producer and consumer.
• Connect: link cause to effect, part to function, force to motion, evidence to conclusion.
• Sequence: place stages of a life cycle, water cycle or process in the correct order.
• Constrain: state the conditions under which a claim is true—especially in investigations and fair tests.
• Explain: use the scientific term inside a complete relationship rather than as a one-word answer.

Command Words Are Science Vocabulary Too

Many lost marks begin before the scientific concept is even retrieved. The student misreads the job encoded by the question. A child who treats state, describe, compare, explain, predict and conclude as interchangeable may know the chapter and still answer the wrong question.

Command	What the answer must do
State / Name	Give the required fact, term, part or outcome directly.
Describe	Say what is observed, changes or happens, usually without needing the full causal mechanism.
Compare	Use the same basis to identify a meaningful similarity or difference.
Explain	Connect scientific ideas and evidence through a cause, mechanism or relationship.
Predict	State what is likely to happen and ground it in the given pattern or scientific relationship.
Conclude	Answer the investigation question using the data or observations as evidence.

The FENCE Test for Science Vocabulary

A useful keyword should stay inside the boundaries of the actual question. Before accepting an answer, ask:

• Fact: Is the scientific term accurate?
• Evidence: What in the question, diagram, table or experiment supports it?
• Need: What exactly is the command word asking the answer to do?
• Connection: Is the relationship between cause, process and result visible?
• Expression: Is the sentence precise enough that another reader can reconstruct the Science?

This is why vocabulary sits naturally beside comprehension. Primary Science questions are written in English, but the student must read them through a scientific lens: identify the conditions, the changed part, the observed result and the exact relationship that the answer must communicate.

How to Study the 100 Words Without Turning Them Into Flashcard Trivia

Pass 1 | Recognition

Can the student recognise the term and give a plain-language meaning? This is the entry level, not the finish line.

Pass 2 | Contrast

Pair terms that students often blur: observation/inference, evaporation/condensation, conductor/insulator, attract/repel, changed/measured/controlled variable. Contrast creates sharper boundaries.

Pass 3 | Representation

Use diagrams, tables, graphs, labelled systems and simple investigations. Ask the student to point to where the keyword lives in the representation.

Pass 4 | Relationship Sentence

Require a sentence that connects at least two scientific ideas: “As ___ increases, ___ decreases”; “Because ___, the ___”; “The ___ carries ___ from ___ to ___”; “The evidence shows ___ because ___.”

Pass 5 | Changed Question

Change the surface. Use a different plant, different numbers, a new diagram or a less familiar context. The student should still recognise the same underlying concept and vocabulary route.

Pass 6 | Retrieval After Delay

Return days or weeks later. A word that only works immediately after revision has not yet become reliable knowledge.

Common Vocabulary Failure Modes

• Keyword dumping: several correct terms are inserted but the answer has no causal structure.
• Near-synonym drift: everyday language replaces a precise scientific relationship.
• Memorised sentence mismatch: a model answer is reproduced even though one condition in the new question has changed.
• Wrong level of detail: the student adds advanced terminology that the syllabus does not require and creates new ways to be inaccurate.
• Observation/inference mixing: an interpretation is presented as if it were directly observed.
• Variable confusion: the changed and measured variables are reversed or controls are listed without explaining why they matter.
• Theme isolation: the child learns “Systems” vocabulary but cannot use it when an Energy or Interaction question crosses into the same system.

Core Syllabus Vocabulary vs Wider Science Enrichment

The older version of this page included useful wider-science words such as earthquake, volcano, tectonic plates, ozone layer, greenhouse effect, fossil fuels, renewable energy, nervous system, immune system, refraction, sound, microscope, Bunsen burner and Petri dish. Those words are not worthless. They broaden a child’s scientific world. But they should not all be presented as if they are explicit core requirements of the current Singapore Primary Science syllabus or guaranteed PSLE vocabulary.

We therefore keep them as an enrichment bridge. A strong student may explore beyond the syllabus. A curious student should absolutely be allowed to ask about volcanoes, cells, climate or laboratory tools. The boundary is simply honest: core learning first; wider Science next.

How Parents Can Use This Hub

Do not ask a child to memorise all 100 in one sitting. Use the school topic as the entry point and diagnose the language that prevents understanding or expression.

• If the child cannot explain a diagram: work on part, function, system, evidence and relationship language.
• If the child confuses experiments: work on observation, variable, fair test, data, comparison and conclusion.
• If open-ended answers are vague: practise cause-and-effect sentences and command-word boundaries.
• If the child memorises model answers: change the context and ask for the same concept again.
• If the child knows the concept but cannot write it: let the student explain aloud first, then compress the spoken reasoning into a precise written answer.

How Tutors Can Use This Hub

A vocabulary check should reveal more than spelling. Ask the student to perform four increasingly difficult actions:

1. Define: What does the word mean?
2. Locate: Where is it visible in this diagram, experiment or system?
3. Relate: What does it affect, carry, change or explain?
4. Transfer: Can the student use it correctly when the context changes?

This turns vocabulary into a diagnostic tool. A student who can define “frictional force” but cannot predict its effect has a different problem from a student who understands the effect but cannot name the force.

The Five Theme Spokes

The master page is intentionally broad. Use the theme pages when a student needs a larger word bank, more examples or deeper topic organisation.

• Top 100 Science “Diversity” Keywords for Primary School Students
• Top 100 Science “Cycles” Keywords for Every Primary School Student
• Top 100 Science Systems Keywords for Every Primary School Student
• Top 100 Science Energy Advanced Keywords for Every Primary School Student
• Top 100 Science Interactions Keywords for Every Primary School Student

Where This Fits in the eduKatePunggol Science Estate

• Science Tuition at eduKatePunggol — commercial/local tuition owner.
• Primary 3 Science Tuition — formal Science entry and observation/classification stage.
• Primary 4 Science Tuition — systems, matter, light and heat progression.
• Primary 5 Science Tuition — reproduction, water, systems and electricity.
• Primary 6 Science Tuition for PSLE — integration and final-year performance.
• How Primary Science Changes from P3 to P6 — educational developmental overview.

Frequently Asked Questions

Does my child need to memorise all 100 words?

No. The useful goal is retrieval and correct use in context. Learn the terms that belong to the current topic, revisit them across different questions, then add new vocabulary as the Science grows.

Are all 100 words guaranteed to appear in PSLE Science?

No. This is a teaching set aligned to the current five-theme Primary Science framework and scientific-practice demands. PSLE assesses concepts and application, not a fixed public list of 100 isolated vocabulary items.

Why include Scientific Practices in a keyword list?

Because students must interpret investigations and evidence. Words such as observation, inference, variable, evidence, conclusion and explanation often control the entire logic of a question even when the topic is plants, forces, matter or electricity.

What if my child knows the keywords but still loses marks?

Then vocabulary may not be the first weak link. Look at evidence selection, cause-and-effect reasoning, interpretation of diagrams, command words, transfer to unfamiliar contexts or examination execution.

Final Principle | Science Words Must Return to Reality

Science vocabulary begins in language, but it should end in a better model of the world. “Root” should help a child explain absorption and transport. “Force” should help them predict motion or deformation. “Evidence” should stop them from claiming more than the data supports. “System” should help them track how parts work together. “Energy conversion” should help them see that change has a structure.

That is the difference between a word list and scientific literacy.

Properly learned Science vocabulary does not decorate an answer. It makes the scientific relationship visible.