Series route: This guide belongs to the complete PSLE Learner’s Guide volume directory. The original PSLE Learning Guide supplies the wider English, Mathematics and Science route, while PSLE Science provide verified subject-specific continuation.
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This volume solves one precise learner problem: the learner observes coloured water climbing and crossing a paper-towel strip but explains it as the towel sucking like a pump or a vacuum, without identifying the fibre spaces and interactions that move water. The goal is durable control, not a remembered slogan. A Primary 6 learner should be able to identify the trigger, explain the mechanism, perform the decision under time pressure and reject an attractive answer that exceeds the evidence.
- Start with the exact mistake and the evidence boundary.
- Build the mechanism before memorising a shortcut.
- Study worked contrasts and name why the near-miss fails.
- Repair misconceptions with one targeted check each.
- Attempt graded independent practice before reading the explanations.
- Return after a delay and prove that the method transfers.
- Use the parent and tutor notes after the learner has attempted the work.
The problem beneath the mistake
Place one end of a paper-towel strip in coloured water and leave the other end higher. Water can rise into the strip and spread beyond the original water level.
The towel contains many fibres with tiny connected spaces between them. These narrow pathways allow capillary action to occur.
Water molecules are attracted to the fibre surfaces. This adhesion helps water wet and move along the solid material.
Water molecules also attract one another. Cohesion helps following water remain connected to water already moving through the pathway.
The combined effect can draw water through narrow spaces, including upward for a limited distance against gravity. No mechanical pump or sealed vacuum chamber is required.
Evaporation from exposed towel can also influence continued movement by removing water farther along the strip. It is a separate process that may contribute to the overall pattern.
The towel does not create water, and colour does not travel independently if it is dissolved in the water. The liquid carries the dissolved colouring through the fibre network.
Rate and distance depend on towel structure, strip width, liquid properties, height difference, contact length and time. A fair comparison changes one intended variable at a time.
In an exam answer, begin with observable movement, name the fibre spaces, describe adhesion to fibres and cohesion within water, then state capillary action as the process.
The safe routine is pathway, interaction, movement, limit: identify the narrow connected spaces, describe water-fibre and water-water attraction, trace the liquid and keep the claim within the evidence.
Core decision: Paper towel contains narrow connected spaces between fibres. Water adheres to the fibres, while cohesion helps water molecules move together, producing capillary action through the strip. This is not evidence of a vacuum or a pump inside the towel.
Liquid movement through a porous material depends on microscopic structure and intermolecular attractions. A named process becomes explanatory only when the pathway, interactions and observed direction are connected.
Mechanism: why the rule works
1. Identify the porous pathway
A paper towel is not a solid sheet at microscopic scale. Interwoven fibres leave many small channels and gaps.
The visible strip supplies a network through which liquid can move rather than a hollow tube or hidden machine.
Diagnostic check. Where is the connected route through the material?
2. Use adhesion
Water is attracted to suitable solid fibre surfaces and wets them. At the edge of the liquid, this attraction can help water spread along the walls of tiny spaces.
Adhesion names the water-to-fibre interaction, not water molecules pulling only on themselves.
Diagnostic check. Which two different materials are attracting?
3. Use cohesion
Water molecules attract other water molecules. When some water advances along a fibre, neighbouring water can follow as part of a connected liquid column or film.
Cohesion names water-to-water attraction and complements adhesion.
Diagnostic check. Which interaction keeps the liquid connected?
4. Name capillary action after the mechanism
Movement through narrow spaces resulting from these interactions is called capillary action.
Merely writing capillary action without the fibre pathway and attractions may name the topic without explaining it.
Diagnostic check. Can you describe how the process produces the observed movement?
5. Include gravity as a limit
Upward movement works against gravity, so the rise is not unlimited. The balance between capillary forces, gravity and evaporation affects the final height and rate.
A towel can move water upward without making gravity disappear.
Diagnostic check. Does the claim state a finite observed movement rather than endless rise?
6. Track dissolved colour correctly
When food colouring is dissolved, it is transported with the water. Different components may interact with paper differently, so the colour front need not always match the water front exactly.
Do not say the paper produces colour or that colour pulls the water.
Diagnostic check. What substance is the moving liquid carrying?
7. Separate evaporation
Evaporation removes liquid water from exposed surfaces as water vapour. This can help sustain movement toward drier regions but is not identical to capillary rise.
A covered and uncovered comparison can test whether evaporation changes the overall rate.
Diagnostic check. Which observation would distinguish liquid movement from evaporation loss?
8. Control structural variables
Thickness, ply count, fibre arrangement, strip width, dipping depth and compression affect the available pathways.
Comparing brands or materials without controlling size and contact can confound the result.
Diagnostic check. Which single feature is the investigation meant to test?
Worked examples: make the decision visible
Pause before each answer. State the controlling evidence in one line, then complete the operation. The explanations deliberately contrast a valid route with a plausible but invalid one, because transfer grows when the learner can say why a tempting route does not apply.
Worked example 1: Upward strip
Task. Explain why coloured water rises above the beaker level in a towel strip.
Reasoning. Narrow fibre spaces provide pathways; adhesion wets the fibres and cohesion brings connected water along.
Answer. Capillary action moves the water upward through the towel for a limited distance.
Independent check. No vacuum is needed.
Contrast-and-transfer pass. Keep the governing principle from “Upward strip”, but change one surface detail in the task: Explain why coloured water rises above the beaker level in a towel strip. Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—Capillary action moves the water upward through the towel for a limited distance.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
Worked example 2: Bridge between cups
Task. A towel connects a fuller cup to a lower empty cup and becomes wet across the bridge.
Reasoning. Capillary action first wets the connected strip; gravity and level differences can then affect continuing flow.
Answer. Water can travel through the towel into the second cup.
Independent check. Do not attribute the whole result to one word without tracing stages.
Contrast-and-transfer pass. Keep the governing principle from “Bridge between cups”, but change one surface detail in the task: A towel connects a fuller cup to a lower empty cup and becomes wet across the bridge. Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—Water can travel through the towel into the second cup.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
Worked example 3: Pump claim
Task. Repair: “The towel pumps the water up.”
Reasoning. A pump supplies mechanical pressure; the towel supplies narrow fibre spaces and surface interactions.
Answer. Water moves by capillary action, not by a hidden pump.
Independent check. The mechanism matches the material structure.
Contrast-and-transfer pass. Keep the governing principle from “Pump claim”, but change one surface detail in the task: Repair: “The towel pumps the water up.” Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—Water moves by capillary action, not by a hidden pump.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
Worked example 4: Vacuum claim
Task. Does the rising water prove a vacuum exists inside the towel?
Reasoning. No sealed low-pressure chamber has been shown.
Answer. The movement can be explained by adhesion, cohesion and narrow spaces.
Independent check. Do not add an unseen cause when the supported mechanism is sufficient.
Contrast-and-transfer pass. Keep the governing principle from “Vacuum claim”, but change one surface detail in the task: Does the rising water prove a vacuum exists inside the towel? Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—The movement can be explained by adhesion, cohesion and narrow spaces.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
Worked example 5: Colour transport
Task. Why does blue colour appear higher on the strip?
Reasoning. The dye is dissolved in the water and travels as the water moves through the towel.
Answer. The moving liquid transports the colouring.
Independent check. Colour is evidence of water movement, with possible separation limits.
Contrast-and-transfer pass. Keep the governing principle from “Colour transport”, but change one surface detail in the task: Why does blue colour appear higher on the strip? Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—The moving liquid transports the colouring.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
Worked example 6: Strip width test
Task. Two strips have different widths and move different amounts of water. Can width alone be credited if dipping depth also differs?
Reasoning. No. Two variables changed.
Answer. The test is not fair for isolating width.
Independent check. Use equal dipping depth and other controls.
Contrast-and-transfer pass. Keep the governing principle from “Strip width test”, but change one surface detail in the task: Two strips have different widths and move different amounts of water. Can width alone be credited if dipping depth also differs? Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—The test is not fair for isolating width.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
Worked example 7: Compressed towel
Task. A tightly pressed section slows movement.
Reasoning. Compression can alter or close the connected spaces and change the pathway.
Answer. A structural change can reduce capillary flow.
Independent check. The explanation stays with fibre geometry.
Contrast-and-transfer pass. Keep the governing principle from “Compressed towel”, but change one surface detail in the task: A tightly pressed section slows movement. Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—A structural change can reduce capillary flow.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
Worked example 8: Covered towel
Task. A covered strip loses less water to air but still becomes wet.
Reasoning. Capillary action can occur without strong evaporation, though evaporation may affect sustained movement.
Answer. The processes are related but distinct.
Independent check. Use comparison evidence rather than claiming evaporation is always essential.
Contrast-and-transfer pass. Keep the governing principle from “Covered towel”, but change one surface detail in the task: A covered strip loses less water to air but still becomes wet. Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—The processes are related but distinct.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
Worked example 9: Different material
Task. A plastic sheet does not carry water like paper towel.
Reasoning. It lacks the same porous connected fibre network and wetting behaviour.
Answer. Material structure and surface interaction matter.
Independent check. Do not say every solid absorbs water.
Contrast-and-transfer pass. Keep the governing principle from “Different material”, but change one surface detail in the task: A plastic sheet does not carry water like paper towel. Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—Material structure and surface interaction matter.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
Worked example 10: Finite rise
Task. Why does water not rise forever?
Reasoning. Gravity opposes upward movement, and the driving surface effects reach a balance while water may evaporate.
Answer. The rise has a practical limit.
Independent check. A correct mechanism includes constraints.
Contrast-and-transfer pass. Keep the governing principle from “Finite rise”, but change one surface detail in the task: Why does water not rise forever? Before recalculating or rewriting, name which evidence remains controlling and which detail has changed. The original conclusion—The rise has a practical limit.—may remain valid only if the changed detail does not alter the trigger, relationship or scope. Use the independent check again rather than trusting visual similarity. This second pass trains selection: the learner must decide whether the same method still applies, adapt one step when a condition changes, and refuse the method when its trigger disappears.
The method lab: change one condition at a time
Draw a magnified paper-towel model with fibres, gaps and a water front. Label adhesion at fibre surfaces and cohesion between neighbouring water molecules.
Design a fair test of strip width using the same towel type, length, dipping depth, water volume, colour concentration, time and height. Decide whether to measure rise distance, transferred mass or both.
Compare capillary action, absorption, gravity-driven flow and evaporation in a four-column table. State which observation each process can explain and where the terms overlap.
Create three alternative explanations—vacuum, pump and colour pulling water—and identify the missing evidence or impossible mechanism in each.
Common misconceptions and targeted repairs
Misconception 1: The towel sucks like a pump
What the learner may think. The learner gives the material an active mechanical action.
Why it fails. No moving pump parts or applied pressure are present.
Targeted repair. Describe narrow spaces, adhesion and cohesion.
Misconception 2: A vacuum pulls the water
What the learner may think. The learner invents low pressure without a sealed system.
Why it fails. Capillary action is sufficient and directly linked to structure.
Targeted repair. Ask what evidence shows a vacuum.
Misconception 3: Colour moves by itself
What the learner may think. The learner separates dissolved dye from its liquid carrier.
Why it fails. The water transports dissolved colouring.
Targeted repair. Track the solvent and solute together.
Misconception 4: Gravity is absent
What the learner may think. The learner assumes upward movement cancels gravity.
Why it fails. Capillary effects oppose gravity over limited distances.
Targeted repair. Include the balance and finite rise.
Misconception 5: Evaporation and capillary action are identical
What the learner may think. The learner uses both terms for any disappearance or movement.
Why it fails. One moves liquid through spaces; the other changes liquid to gas at a surface.
Targeted repair. Name state and location for each process.
Misconception 6: Any absorbent comparison is fair
What the learner may think. The learner changes width, thickness and material at once.
Why it fails. Structure controls the pathway, so multiple changes prevent isolation.
Targeted repair. Keep all but one variable constant.
Graded independent practice with explained answers
Attempt each item without looking ahead. Write the evidence or relationship before the final response. Early items check recognition; middle items require explanation; later items change the surface form so that copying a worked example is insufficient.
Practice 1: Pathway
Question. What feature of paper towel allows water routes?
Explained answer. Tiny connected spaces between fibres.
Why this earns trust. The physical pathway is identified.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “Tiny connected spaces between fibres.” from memory, but to recreate a justified answer from the new evidence.
Practice 2: Adhesion
Question. What does adhesion describe here?
Explained answer. Attraction between water and fibre surfaces.
Why this earns trust. Different materials are linked.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “Attraction between water and fibre surfaces.” from memory, but to recreate a justified answer from the new evidence.
Practice 3: Cohesion
Question. What does cohesion describe?
Explained answer. Attraction among water molecules that helps them move together.
Why this earns trust. The liquid remains connected.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “Attraction among water molecules that helps them move together.” from memory, but to recreate a justified answer from the new evidence.
Practice 4: Process
Question. Name the combined movement through narrow spaces.
Explained answer. Capillary action.
Why this earns trust. The name follows the mechanism.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “Capillary action.” from memory, but to recreate a justified answer from the new evidence.
Practice 5: Vacuum
Question. Does upward movement prove a vacuum?
Explained answer. No. Capillary action explains it without a sealed low-pressure region.
Why this earns trust. Unsupported cause is rejected.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “No. Capillary action explains it without a sealed low-pressure region.” from memory, but to recreate a justified answer from the new evidence.
Practice 6: Colour
Question. Why does food colouring travel?
Explained answer. It is dissolved in and carried by moving water.
Why this earns trust. The carrier is stated.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “It is dissolved in and carried by moving water.” from memory, but to recreate a justified answer from the new evidence.
Practice 7: Gravity
Question. Why is the rise limited?
Explained answer. Gravity opposes upward movement and a balance is reached.
Why this earns trust. The mechanism has a constraint.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “Gravity opposes upward movement and a balance is reached.” from memory, but to recreate a justified answer from the new evidence.
Practice 8: Evaporation
Question. How is evaporation different?
Explained answer. It changes liquid water at a surface into water vapour.
Why this earns trust. State change is separated from liquid transport.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “It changes liquid water at a surface into water vapour.” from memory, but to recreate a justified answer from the new evidence.
Practice 9: Fair test
Question. Name three controls for comparing towel types.
Explained answer. Strip dimensions, dipping depth and time; water conditions should also match.
Why this earns trust. Structural comparisons are isolated.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “Strip dimensions, dipping depth and time; water conditions should also match.” from memory, but to recreate a justified answer from the new evidence.
Practice 10: Measurement
Question. Give one useful dependent variable.
Explained answer. Rise distance or mass/volume transferred in a set time.
Why this earns trust. The observation is measurable.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “Rise distance or mass/volume transferred in a set time.” from memory, but to recreate a justified answer from the new evidence.
Practice 11: Repair
Question. Improve “The paper drinks water.”
Explained answer. Water moves through narrow fibre spaces by capillary action involving adhesion and cohesion.
Why this earns trust. Metaphor is replaced by mechanism.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “Water moves through narrow fibre spaces by capillary action involving adhesion and cohesion.” from memory, but to recreate a justified answer from the new evidence.
Practice 12: Routine
Question. State the safe answer sequence.
Explained answer. Identify fibre spaces, describe adhesion and cohesion, trace water movement and state limits or controls.
Why this earns trust. The causal chain is complete.
Transfer variation. Close the answer, wait several minutes, and rebuild the reasoning with different names, values or wording while preserving the same decision. Start by stating the evidence that activates the method; then produce the response and a separate check. If the new surface detail changes the governing condition, explain why the earlier answer pattern must not be copied. The aim is not to repeat “Identify fibre spaces, describe adhesion and cohesion, trace water movement and state limits or controls.” from memory, but to recreate a justified answer from the new evidence.
A four-session mastery cycle
Session 1: construct. Read the mechanism once, cover it and write a three-line model containing the trigger, the operation and the check. Add one example and one near-miss. Compare only after the model is complete. If the operation is right but the trigger is missing, the knowledge is unsafe because it may be applied in the wrong place.
Session 2: discriminate. Mix six items: two that clearly require this method, two that tempt the method but violate a condition, and two that require another skill. For every item, write “use” or “do not use” before answering. Accuracy in method selection matters more than speed at this stage.
Session 3: explain. Give a complete answer to an imagined classmate. Include the smallest sufficient evidence, the mechanism and the independent check. Remove any sentence that merely repeats the question or adds an unsupported claim. A concise causal explanation is stronger than a longer collection of familiar words.
Session 4: perform. Attempt a timed mixed set without notes. Mark uncertain decisions, but continue. During review, classify each error as trigger, evidence, operation, scope, unit or check. Reattempt one changed version after a delay. Mastery is shown when the learner chooses and adapts the method without needing the original example beside it.
Delayed transfer: prove that the learning lasts
Transfer test 1: Material comparison
After two days, explain why cloth, soil or a thin tube may show related movement.
Success criterion. The learner checks pathways and wetting rather than copying the paper label.
Transfer test 2: Variable audit
Diagnose tests with different widths, times and dipping depths.
Success criterion. Every confound is identified before a conclusion.
Transfer test 3: Process separation
Classify observations under capillary transport, gravity flow and evaporation.
Success criterion. State and direction evidence support each choice.
Transfer test 4: Blank-page model
Draw fibres, water front and two attraction labels from memory.
Success criterion. The explanation remains mechanistic without the original example.
Examination control
1. Name the structure. Paper fibres create narrow connected spaces.
2. Use both interactions. Adhesion links water to fibres; cohesion links water to water.
3. Trace the liquid. State where it starts and where it moves.
4. Reject invented machinery. No pump or vacuum is required.
5. Audit fairness. Control strip geometry, contact and time.
Under time pressure, compress the method to fibre spaces → adhesion → cohesion → capillary movement → limit and controls. The compressed routine is useful only after the full reasoning is understood. If it produces uncertainty, expand the step instead of guessing.
A compact error log
Label errors as pathway omitted, adhesion-cohesion reversed, pump invented, vacuum invented, colour treated independently, gravity ignored, evaporation merged or fair-test variable missed.
Retest with a different porous material. The learner should inspect structure and interaction before naming the process.
Notes for parents and tutors
Use only small amounts of ordinary water and washable colouring, with adult supervision for spills; no special chemicals are needed.
Ask the learner to draw a magnified fibre model instead of saying the towel drinks.
Measure at fixed times so a visual demonstration becomes a controlled observation.
Praise answers that state both what the process explains and what it does not prove.
Frequently asked questions
Is paper towel hollow like a straw?
No. It contains many tiny connected spaces among fibres.
Why does water move upward?
Adhesion, cohesion and narrow pathways produce capillary action that can oppose gravity over a limited distance.
Is a vacuum involved?
Not in the usual open-strip demonstration.
Does the towel pump?
No. It has no mechanical pumping action.
Why does colour travel?
Dissolved dye is carried by the moving water.
Does evaporation matter?
It can influence continued movement, but it is distinct from capillary transport.
What makes a fair comparison?
Match strip size, contact depth, liquid conditions, time and height while changing one factor.
What is the strongest exam explanation?
Water moves through narrow fibre spaces by capillary action due to adhesion to fibres and cohesion among water molecules.
Next routes
Return to the complete volume directory to locate the series, use the original PSLE Learning Guide for the foundation route, and continue through PSLE Science for verified subject guidance. The next useful task is a mixed set in which this idea is sometimes relevant and sometimes irrelevant; that is where the learner must choose a method rather than imitate one.