Master Primary 5 Vocabulary | Top 100 Words for Electrical Systems and Circuits

A child may recognise every object in a circuit picture and still be unable to explain why the bulb stays dark. The missing step is often a relationship: which contact must connect to which part, where the gap lies, or which path remains complete. Vocabulary helps when it makes that relationship visible.

Consider two answers to the same diagram. “The bulb is not working because there is no electricity” repeats the result without locating a cause. “The switch is open, so there is a gap in the conducting path and current cannot flow through the bulb” identifies the relevant change. The second answer is clearer because each word has a job.

Use the list in three passes. First, recognise and explain the word in ordinary speech. Second, connect it to a labelled picture, an observation or a short passage. Third, use it in a sentence whose meaning can be checked. If a child says “closed means shut”, ask what is closed in a circuit: the conducting path must be complete. That extra step turns a familiar everyday word into useful subject language.

The MOE 2023 Primary Science syllabus places Electrical System at Primary 5. Standard Science includes constructing circuits, investigating suitable battery and bulb arrangements, and identifying conductors and insulators. The Foundation treatment is narrower. Valour Primary School’s published 2026 science plan also lists electrical systems at Primary 5. Follow the sequence and depth set by your own child’s school.

The first groups below establish the parts and connections. Later groups add investigation language and the small linking words that hold an explanation together. A child who already knows wire can still benefit from explaining the conducting material inside it and the insulating covering outside it. Difficulty should come from increasingly accurate thinking, not merely from increasingly unusual words.

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The numbers identify the 100 target words. The meanings describe the sense used in this topic, and the sentences are original teaching examples. A word may have other meanings in a different context.

1–10. Name the parts before explaining the system

These words name the whole system and its parts. Point to a part in a school diagram, say its name, and explain its job. A label becomes useful when it connects an object to a function.

No.	Word	Meaning	Example sentence
1	circuit noun	A connected arrangement that can provide a path for electric current when the path is complete.	Mei traced the circuit from one battery terminal, through the bulb, and back to the other terminal.
2	system noun	A set of connected parts that work together to perform a function.	The electrical system needed a suitable energy source, connecting wires and a working bulb to produce light.
3	component noun	An individual part that has a particular job within a larger system.	The switch was the component that allowed Arun to open or close the circuit without removing a wire.
4	cell noun	A single electrical energy source that uses chemical changes to supply energy to a circuit.	The teacher placed one cell in the holder and checked that the school bulb was suitable for it.
5	battery noun	An electrical energy source; everyday language uses this word for one cell or several connected cells.	The battery supplied energy to the circuit, but it could not make the bulb light across an open gap.
6	bulb noun	A component designed to produce light when a suitable electric current passes through it.	The small bulb glowed after its two contacts became part of a complete circuit with the cell.
7	wire noun	A long, thin conductor used to connect circuit components, often covered with an insulating material.	A copper wire inside the plastic coating connected the battery holder to the bulb holder in our kit.
8	switch noun	A component used to make or break a conducting path in an electrical circuit.	Opening the switch created a gap, so the bulb in this simple circuit went out immediately.
9	terminal noun	A connection point on a cell, battery or other electrical component.	The circuit had to connect with both battery terminals through the intended components, rather than touch only one.
10	contact noun	A place where conducting parts touch and allow an electrical connection to be made.	A loose contact at the bulb holder interrupted the path even though the wire looked correctly positioned.

11–20. Describe whether the path is complete

Look at the path before guessing about brightness. These words help you explain the difference between a drawing that looks joined and a circuit with the required conducting connections.

No.	Word	Meaning	Example sentence
11	complete adjective	Having the necessary parts connected into an unbroken conducting path through the intended components.	The diagram showed a complete path through the bulb and back to the battery, with no missing connection.
12	closed adjective	Describing a circuit or path in which current can flow because the conducting route is unbroken.	The closed circuit allowed current to pass through the working bulb when a suitable battery supplied energy.
13	open adjective	Describing a circuit or path interrupted by a gap that prevents current from flowing along it.	An open switch stopped current in that branch, although another correctly connected parallel branch could still work.
14	broken adjective	Interrupted or damaged so that the intended connection or function is no longer continuous.	The broken wire left a gap in the simple circuit, preventing the current from flowing through the bulb.
15	connect verb	To join parts so that they can form the intended link or conducting path.	Under the teacher's guidance, the pupils connected each wire to the correct contact on the school kit.
16	disconnect verb	To separate an electrical connection and interrupt the path it previously provided.	The teacher disconnected the battery holder before the group changed the arrangement of the circuit components.
17	gap noun	A space between parts that interrupts the intended conducting path.	The tiny gap between the metal clip and the terminal explained why the bulb would not light.
18	loop noun	A route that returns to its starting point; in a simple circuit, it must also conduct current.	Drawing a neat loop was insufficient because one section was plastic and did not provide a conducting path.
19	pathway noun	The route along which something can travel; here, the route available to electric current.	The pupils traced the conducting pathway through the bulb instead of judging the circuit by its overall shape.
20	junction noun	A point where conducting paths meet or separate in a circuit.	At the junction in the parallel circuit, the drawing showed two separate branches connected to the battery.

21–30. Explain the materials and their properties

Use conductor and insulator to describe electrical behaviour in the classroom conditions being discussed. The colour, cost or shininess of an object does not reliably tell you how it behaves in a circuit.

No.	Word	Meaning	Example sentence
21	conductor noun	A material through which electric current can pass relatively easily under the conditions being considered.	The metal strip acted as a conductor when it completed the gap in the teacher's test circuit.
22	insulator noun	A material that strongly resists the passage of electric current in the conditions being considered.	The dry plastic strip acted as an insulator in the low-voltage classroom test, so the bulb stayed unlit.
23	metal noun	A class of materials whose members generally conduct electricity well, though objects may have insulating coatings.	The object contained metal, but paint over its surface prevented the clip from making a good electrical contact.
24	copper noun	A metal commonly used for the conducting part of electrical wires.	The cable contained copper to carry current, while its outer covering had a different job to perform.
25	aluminium noun	A lightweight metal that can conduct electric current.	The teacher's prepared aluminium sample completed the test circuit when the clips made suitable contact with its surface.
26	plastic noun	A group of materials, many of which are useful electrical insulators in ordinary classroom conditions.	The plastic covering separated the conducting wire from the child's hand during the supervised school-kit activity.
27	rubber noun	An elastic material; suitable rubber materials can provide electrical insulation in appropriate conditions.	The class identified rubber as an example of an insulating material without treating any rubber object as safety equipment.
28	material noun	The substance from which an object or part of an object is made.	To explain the result, Hana named the material in the connecting strip rather than merely describing its colour.
29	coating noun	A layer covering the surface of another material.	The insulating coating had to be distinguished from the metal inside when the pupils discussed the wire's construction.
30	property noun	A feature of a material that helps explain how it behaves or what it can be used for.	Electrical conductivity was the property being investigated; the strip's length and shape were kept the same where possible.

31–40. Read arrangements and make controlled changes

These terms help you describe where components are connected. Series and parallel describe connections, not whether the wires happen to look straight, round, tidy or symmetrical on the page.

No.	Word	Meaning	Example sentence
31	series noun/adjective	An arrangement in which components lie along the same single path, one after another.	Both identical bulbs were connected in series, so a break anywhere in their shared path stopped both from lighting.
32	parallel adjective	An arrangement in which components are connected on separate branches between the same two connection points.	The two bulbs were connected in parallel, with a separate complete branch available through each working bulb.
33	branch noun	One of the separate paths in a circuit with more than one route.	Opening the switch in one branch did not break the other branch in the diagram the teacher provided.
34	arrangement noun	The way parts are organised and connected in relation to one another.	The number of bulbs stayed the same, but changing their arrangement altered the paths available to the current.
35	position noun	The place occupied by a component within a drawing or system.	Moving the drawn bulb to a different position on the page did not automatically change its electrical connections.
36	identical adjective	The same in the relevant features needed for a fair comparison.	The group used identical bulbs so that differences in bulb type did not confuse their comparison of brightness.
37	additional adjective	Extra; added to what was already present.	The question asked about an additional identical bulb in series, so the pupil checked that the battery arrangement stayed unchanged.
38	remove verb	To take a component away from its place in an arrangement.	Before predicting what would happen, Ravi checked whether removing the bulb would leave an open gap in the circuit.
39	replace verb	To put another item in the place of the original one.	The teacher replaced the faulty bulb with a working bulb of the same type before the group repeated its observation.
40	trace verb	To follow a route carefully from one point to another.	Lina traced each complete path through the diagram before deciding which bulbs would remain lit when the switch opened.

41–50. Talk accurately about current and energy

Current and energy answer different questions. Current describes moving electric charge. Energy explains how the circuit can produce light, heating or movement. Learning both meanings prevents a common explanation error.

No.	Word	Meaning	Example sentence
41	current noun	The flow of electric charge through a conducting path.	Current flowed through the closed simple circuit, and the working bulb produced light and warmed its surroundings.
42	energy noun	A quantity transferred or converted when changes happen, such as a bulb producing light and heat.	The battery supplied energy to the circuit; the pupil did not describe the current as being used up by the bulb.
43	electrical adjective	Relating to electricity, electric circuits or the energy transferred through them.	The pupils studied an electrical system and explained how its connected components allowed the intended device to work.
44	chemical adjective	Relating to substances and changes involving their composition; here, describing energy stored in a cell.	The cell's chemical energy store decreased as it supplied energy to the working circuit over time.
45	light noun	The form of energy that enables us to see illuminated objects.	The bulb produced light, allowing the pupils to observe whether it was working in the completed circuit.
46	heat noun	Energy transferred because of a temperature difference; in school explanations, often discussed as a heating effect.	The bulb also warmed its surroundings, so its output was not limited to the light that the pupils could see.
47	transfer verb	To pass energy from one part of a system to another.	The completed circuit allowed energy to transfer from the battery to the bulb and then to the surroundings.
48	convert verb	To change energy from one form to another.	The model motor converted some of the electrical energy it received into the energy of movement when its circuit was complete.
49	supply verb/noun	To provide something needed; in a circuit, the energy source supplies energy to connected components.	A fresh suitable cell could supply energy, but the open switch still prevented current from flowing through the bulb.
50	source noun	The place or device from which something is obtained.	The battery was the energy source in this model, while the switch controlled whether the conducting path was complete.

51–60. Describe results without making careless claims

A comparison needs a reference. Brighter than which bulb? Changed from which arrangement? These words help a child state the result precisely and retain the conditions that make the statement true.

No.	Word	Meaning	Example sentence
51	bright adjective	Giving out a relatively large amount of light in the comparison being made.	The bulb appeared bright compared with the same bulb in the earlier circuit containing an additional identical bulb in series.
52	dim adjective	Giving out relatively little light compared with a stated reference.	The two bulbs were dim compared with the single-bulb arrangement powered by the same suitable cell.
53	brightness noun	How much light a source appears to give out in the conditions of observation.	The pupils compared brightness under the same room lighting so that a change in surroundings would not mislead them.
54	increase verb/noun	To become greater, or a change towards a larger amount.	Within the kit's approved arrangement, the teacher showed how adding a suitable cell in series could increase bulb brightness.
55	decrease verb/noun	To become smaller, or a change towards a lower amount.	The bulb's brightness could decrease when another identical bulb was added in series while the suitable battery supply stayed unchanged.
56	compare verb	To examine two or more things and identify relevant similarities or differences.	The class compared the same bulb types under controlled conditions instead of comparing unrelated lamps from different rooms.
57	equal adjective	The same in an amount or feature being considered.	The answer said the identical bulbs had equal brightness in the stated symmetrical arrangement, not that all bulbs are always equal.
58	unchanged adjective	Remaining the same as before in the feature being discussed.	The battery arrangement remained unchanged while the pupils investigated the effect of changing the number of bulbs in series.
59	affect verb	To produce a change in something or influence what happens.	A loose connection could affect the result, so the group checked each contact before recording its observation.
60	depend verb	To be determined or influenced by particular conditions.	The correct brightness prediction would depend on the connections, bulb types and energy source described in the question.

61–70. Investigate and use evidence

These words separate a sensible prediction from an observed result. They also make it easier to discuss a surprising outcome calmly, without immediately deciding that the child or experiment has failed.

No.	Word	Meaning	Example sentence
61	observe verb	To notice and record what happens using the appropriate senses or equipment.	The pupils observed which bulbs lit before attempting to explain why the circuit behaved in that way.
62	observation noun	A record of what was noticed or measured during an investigation.	Our observation was that the bulb remained unlit; the explanation required further checks of the circuit and its components.
63	predict verb	To state what you expect to happen using relevant knowledge and the given conditions.	Before changing the diagram, the teacher asked us to predict whether the remaining branch would still have a complete path.
64	prediction noun	An expectation about what will happen, supported by knowledge or evidence.	Her prediction included a reason, so the group could discuss the idea even if the actual result was unexpected.
65	investigate verb	To examine a question carefully by collecting and considering relevant evidence.	The class used a teacher-approved kit to investigate whether selected dry samples allowed the test bulb to light.
66	variable noun	A factor that can change or be changed in an investigation.	The number of identical bulbs in series was the variable the group changed while keeping the battery arrangement constant.
67	control verb	To keep a relevant factor fixed or manage it so that a comparison is meaningful.	We controlled the type of bulb because a different bulb could change the result for another reason.
68	fair adjective	Designed so that the intended change can be compared without avoidable differences confusing the result.	The comparison was fair because the groups used the same type of working bulbs and the same suitable battery arrangement.
69	evidence noun	Relevant information that supports or challenges a claim.	The repeated result provided evidence about the tested sample, but one unlit bulb alone did not prove that the sample was an insulator.
70	conclusion noun	A judgement reached after considering the question, observations and limits of the evidence.	The conclusion described how the sample behaved in that test instead of making an unlimited claim about every similar object.

71–80. Read the task and build the explanation

These instruction words tell you what kind of answer is needed. Naming, describing and explaining are connected skills, but they do not ask for exactly the same response.

No.	Word	Meaning	Example sentence
71	diagram noun	A simplified drawing that shows important parts and relationships.	The circuit diagram used clear symbols so the reader could follow the connections without needing a detailed picture of the equipment.
72	symbol noun	A mark used to represent an object or idea in a consistent way.	The pupil checked the switch symbol carefully because its open position changed whether the branch formed a complete path.
73	label noun/verb	A name attached to part of a diagram, or the act of adding that name.	A clear label identified the energy source, while a separate sentence explained what that source provided to the circuit.
74	represent verb	To stand for or show something using a drawing, symbol, word or model.	The straight lines represented connecting wires; their neat appearance did not tell us that every crossing was an electrical junction.
75	describe verb	To state relevant features or report what happens.	When asked to describe the result, the pupil wrote that both bulbs went out after the shared switch was opened.
76	explain verb	To show why or how something happens by linking the result to a relevant reason.	To explain the result, she added that opening the shared switch broke the only complete path through both bulbs.
77	identify verb	To name or recognise the particular thing requested.	The question asked us to identify the insulator, so we selected the sample supported by the controlled test results.
78	classify verb	To place items into groups according to a stated feature.	We classified the tested materials by their electrical behaviour rather than grouping them according to colour or size.
79	infer verb	To work out a reasonable meaning or conclusion from evidence and relevant knowledge.	From the labelled connections, we could infer that both bulbs shared one path even though they were drawn far apart.
80	justify verb	To support an answer or decision with a relevant reason or evidence.	Rina justified her prediction by tracing the unbroken branch that remained connected across the battery after the other branch opened.

81–90. Use electricity responsibly

Safety words need to lead to sensible actions. Learning how a school circuit works does not prepare a child to inspect, repair or experiment with household electrical wiring.

No.	Word	Meaning	Example sentence
81	cautious adjective	Taking care because an action may involve a risk or an uncertainty.	The cautious pupil stopped using the school kit and told the teacher when a component became unexpectedly warm.
82	supervised adjective	Carried out while a responsible adult guides the activity and checks what is happening.	Circuit construction was a supervised lesson using the equipment and arrangements approved by the teacher.
83	damage noun/verb	Harm that makes something less safe or prevents it from working correctly.	Visible damage to a cable was something to report to an adult, rather than investigate by touching the exposed area.
84	exposed adjective	Uncovered or left without the intended protection.	The pupils learned that exposed household wires must not be handled, even if an appliance appears to be switched off.
85	dry adjective	Free from liquid on the surface or in the relevant material.	The teacher kept the working area dry and used only the prepared samples intended for the low-voltage classroom activity.
86	overload verb/noun	To demand more from an electrical supply or device than it is designed to handle.	The family asked an adult to manage appliance use sensibly so that a socket or extension device was not overloaded.
87	hazard noun	Something that could cause harm if the risk is not managed.	A damaged plug was a hazard to report, not an object for the child to open during a science investigation.
88	appliance noun	A device designed to perform a household task, often using electricity.	The child observed the appliance from a safe distance and discussed its purpose without removing its cover or touching its wiring.
89	conserve verb	To use a resource carefully and avoid unnecessary waste.	We can conserve electrical energy by switching off lights that are not needed, following the household's normal safe routine.
90	efficient adjective	Achieving a useful result while wasting relatively little energy or other resources.	An efficient device can provide a useful result with less wasted energy, although comparisons must consider what each device actually does.

91–100. Link reasons, conditions and comparisons

Small linking words can change the meaning of an entire answer. Practise them inside complete sentences. The aim is to make the relationship clear, not to add a complicated word to every line.

No.	Word	Meaning	Example sentence
91	because conjunction	Introduces a reason for the statement it connects to.	The bulb went out because opening the switch broke the only complete conducting path in the simple circuit.
92	therefore adverb	Introduces a result or conclusion that follows from the reason already given.	The switch created a gap in the shared path; therefore, neither bulb in that series circuit remained lit.
93	however adverb	Introduces a contrast with the previous statement or an important limit to it.	The sample looked metallic; however, its coated surface did not make a conducting connection with the clips.
94	whereas conjunction	Connects two contrasting facts or situations.	The series arrangement had one path through both bulbs, whereas the parallel arrangement had a separate branch through each bulb.
95	although conjunction	Introduces a fact that contrasts with what happens in the main part of the sentence.	Although the wire touched the holder, it did not touch the correct conducting contact needed to complete the circuit.
96	unless conjunction	Introduces a condition that must be met for a different outcome to become possible.	The bulb will remain unlit unless the open gap is closed and the other required circuit conditions are satisfied.
97	if conjunction	Introduces a condition on which the following statement depends.	If the shared switch is opened, both bulbs will go out because their only complete paths will be interrupted.
98	both determiner/pronoun	Refers to two named people or things together.	Both identical bulbs went out when the switch in their common series path was opened.
99	neither determiner/pronoun	Means not one and not the other of two named things.	Neither bulb lit because the shared battery connection was missing, leaving no complete path through either branch.
100	respectively adverb	Matches items in one list to items in another list in the same order.	The plastic and copper samples acted as an insulator and a conductor, respectively, in the teacher's prepared test circuit.

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1. A complete path is necessary, but it is not the only condition

For the simple classroom circuits considered here, current needs a closed conducting path. A suitable energy source and working components are also required. Therefore, “the circuit is closed” does not by itself prove that a particular bulb must glow. The battery may be exhausted, the bulb may be faulty, or a connection may not be what the drawing appears to suggest.

Teach the child to state the known conditions. “With the working bulb and suitable battery shown, closing the switch completes the circuit and the bulb lights” is a stronger explanation than “closed circuits always light bulbs”. It describes the actual model without pretending to cover every electrical device.

2. A conductor is a material, not a guarantee about the whole object

A metal object may have paint or plastic over the part touching a clip. In that situation, the circuit may not make a conducting connection even though metal is present. A child should distinguish the material inside an object from the surface that actually touches the circuit.

A negative result also needs checking. If a test bulb does not light, the material may be an insulator in that test, but a weak cell, faulty bulb or poor contact could produce the same observation. First establish that the test circuit works with a suitable known conductor. Then discuss what the comparison supports. This is evidence-based classification, rather than guessing from appearance.

3. Current is not the same as energy

In a simple series circuit, avoid saying that the first bulb “uses up the current” and leaves less for the next bulb. The current is not consumed in that way. The battery supplies energy, and components transfer or convert energy while the circuit operates. The words current flows and energy transfers help keep the ideas separate.

A useful classroom analogy is a delivery route, provided its limit is stated: a circulating route can carry something without the route itself being used up. Do not turn the analogy into a claim that electricity consists of tiny parcels of light. Return to the circuit and use the actual scientific terms.

4. Series and parallel describe connections

Two bulbs can be drawn beside each other yet still lie along one shared series path. They can also be drawn far apart while connected across the same two points in parallel. Trace the connections. Do not decide from the shape of the drawing, the length of its lines, or the position of the bulbs on the page.

For Primary 5 Standard practice, ask what happens if a particular branch opens. Another branch may remain complete if its own connections and the shared supply path are intact. If the break is in a shared connection to the battery, several branches may stop working. “Parallel means the other bulb always stays on” loses that important condition.

5. A brightness comparison needs controlled conditions

In the usual suitable school-kit comparison, adding another identical bulb in series to the same battery makes the bulbs dimmer than the single-bulb arrangement. That statement includes the conditions that make the comparison meaningful. Changing bulb type, battery arrangement and connections at the same time would create a different question.

Similarly, do not write “all parallel bulbs are equally bright” as an unlimited rule. A question may specify identical bulbs on equivalent branches across the same supply. Use those details. Words such as identical, same, unchanged and under these conditions are often more useful than a dramatic adjective.

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Case A: The bulb stays dark after the switch is closed

Situation: A teacher provides a suitable low-voltage kit with one working cell, one working bulb, a switch and connecting wires. The switch is closed, but one clip touches the plastic outer covering of a wire instead of the intended metal connector. The bulb does not light.

First attempt: “The battery is not strong enough.” This is a possible explanation for some dark bulbs, but it ignores the information given: the cell and bulb have already been checked. The useful evidence is the contact with plastic.

Improved answer: “The clip touches the insulating plastic covering, so there is no continuous conducting path through that connection. Current cannot flow through the bulb in this circuit.” This answer names the relevant material, explains the interrupted relationship and connects it to the result.

Parent prompt: “Which detail in the situation supports your answer?” The child should point to the plastic covering, not merely repeat “insulator”. Then ask for a counterexample: “Would every wire covered in plastic fail to work?” No. Proper connecting wires are designed with suitable conducting contacts at their connection points; the insulation elsewhere does not prevent the intended internal path from working.

Case B: One branch opens, but another bulb remains lit

Situation: A diagram shows two identical working bulbs on separate parallel branches connected across the same suitable battery. Each branch has its own switch. The shared wires from the battery are intact. Switch A is opened while switch B remains closed.

First attempt: “Bulb B stays on because it is parallel.” The keyword is relevant, but the explanation is incomplete. It does not identify the surviving path or the location of the break.

Improved answer: “Opening switch A breaks the path through bulb A. The branch containing bulb B still forms a complete conducting path across the battery, so current can continue to flow through bulb B.” Notice how through, containing and across help describe the connections.

Extension question: What changes if the open switch is placed in the shared wire before the branches separate? Both bulbs go out because neither branch has a complete path through the shared battery connection. The child should trace again rather than reuse the previous answer automatically.

These cases show why vocabulary should return to the diagram. A remembered definition is a starting point. A successful explanation selects the definition that fits the evidence, keeps the conditions and identifies the relevant cause.

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Read this original teaching passage. It is a practice text written for this guide, not an official examination passage.

Nadia and Wei were preparing a small battery-powered display during a supervised science lesson. Their teacher provided a circuit kit, checked the components and explained which arrangements were suitable. The pupils first drew their plan. It showed two identical bulbs in series and a switch in the shared path.

When the teacher approved the assembly, both bulbs lit. Nadia noticed that they looked dimmer than the single bulb in the earlier demonstration. Wei wanted to write, “The first bulb uses up some current.” Nadia paused. They had been reminded that current was not consumed by the first bulb in that way. They described the change in brightness and stated that the number of identical bulbs in series had increased while the battery arrangement remained unchanged.

Next, the teacher supplied a diagram with a separate branch for each bulb. Both branches were connected across the same battery. Each contained its own switch. The pupils predicted that opening one branch would leave the other bulb lit, provided that the shared connections and the other branch remained complete.

The first trial did not match their prediction. Neither bulb lit. Instead of immediately rejecting their idea, they reported the observation to the teacher. A clip in the shared connection had not been attached correctly. After the teacher corrected that connection, they repeated the approved test. Opening one branch now left the other bulb lit.

In their conclusion, the pupils recorded both the result and the condition that made it possible. They also explained why the unsuccessful trial had not provided a fair test of their original prediction. Their display had become a useful investigation because they checked the path before deciding what the evidence meant.

Questions and model answers

1. What does “identical” tell you about the bulbs? They were the same in the relevant features needed for the comparison, so differences in bulb type were not the intended explanation for the brightness change.
2. Which factor changed in the first comparison? The number of identical bulbs in series increased. The passage states that the battery arrangement remained unchanged.
3. Why did Nadia reject Wei’s proposed sentence? It incorrectly suggested that the first bulb consumed current and left less for the next bulb. Their explanation needed to distinguish current from energy.
4. What condition did the parallel-circuit prediction include? The shared connections and the other branch had to remain complete. Merely naming a parallel arrangement was insufficient.
5. Why did neither bulb light in the first parallel trial? An incorrectly attached clip interrupted a shared connection. The passage provides that cause; there is no need to invent a flat battery.
6. What does “provided that” mean in the passage? It introduces a condition: the prediction holds if the stated connections remain complete.

For a second reading, ask your child to underline one observation and circle one explanation. “Neither bulb lit” reports what happened. The sentence about the shared clip explains why. Being able to separate the two helps in both science answers and English comprehension.

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Build a word family without changing the meaning carelessly

Start with connect. It is an action: “Connect the correct parts in the teacher’s diagram.” Connection names the link: “Check the connection beside the switch.” Disconnect introduces the opposite action: “The teacher disconnected the battery holder.” Disconnected can describe the resulting state: “The battery holder was disconnected.” These forms belong to the same word family, but they fit different places in a sentence.

Now try observe and observation, both found in the numbered bank. Complete these sentences: “We will _____ which bulbs light.” “Our _____ was that bulb B remained lit.” The answers are observe and observation. Ask the child to explain the difference: the first names an action, while the second names the record of what was noticed. This is more useful than memorising the ending without considering the sentence.

Use predict and prediction in the same way. “I predict that the bulb will remain lit” becomes “My prediction is that the bulb will remain lit.” The scientific claim stays the same while the grammar changes. Word-family forms discussed here are practice extensions to the 100 numbered entries, not extra entries in the list.

Use the nearby words as evidence

Read: “The pupils added an additional bulb, increasing the number from one to two.” What does additional mean? The change from one to two shows that another bulb was added. Now replace the word with identical. The sentence would tell you about sameness, not simply about an extra item. A word that sounds plausible can still express a different idea.

Read: “The outer covering had split, leaving the wire exposed.” The surrounding description suggests that exposed means uncovered. The next useful action is to report damaged equipment to an adult, not to test the guessed meaning by handling it. Context helps understanding; it does not make an unfamiliar object safe.

Some contexts are insufficient. “The component was affected” tells you that something influenced it, but not exactly what changed. Ask for the missing result: did the bulb become dimmer, stop lighting, or remain unchanged while another component changed? A precise reader notices when the evidence does not support a specific answer.

Explain aloud before writing

Give the child a familiar diagram and ask for three spoken sentences: “I observe…”, “This happens because…”, and “If we change…, then…”. The listener should be able to identify the component, the result and the relevant condition without guessing which “it” or “that” the speaker means.

Switch roles. Let the child listen while the adult deliberately gives an incomplete explanation such as “It stays on because it is parallel.” The child can ask, “Which bulb? Which branch stays complete?” This makes the learner an active checker of meaning. Finish by writing the clearest version together, preserving the child's successful explanation rather than replacing it with a more elaborate paragraph.

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Strong subject writing is not a contest to include the greatest number of technical words. A short answer can be excellent if it identifies the correct feature and links it to the requested result. Start with the sentence the child can already produce, then repair one problem at a time.

Repair vague nouns

Before: “It cannot go because that is open.” After: “Current cannot flow through bulb A because switch A leaves a gap in its branch.” The revision replaces unclear pronouns with the particular current, bulb, switch and branch involved. It becomes possible for another reader to check the claim against the diagram.

Repair missing conditions

Before: “Adding batteries makes bulbs brighter.” After: “In the approved school-kit arrangement, adding a suitable cell in series can make the same bulb brighter.” The added conditions prevent the sentence from becoming advice to connect arbitrary batteries or to exceed a component’s rating. Practical changes remain the teacher’s responsibility.

Repair a false reason

Before: “The bulb is dim because the wires are drawn longer.” After: “The diagram does not state that the actual wires differ. I should compare the stated battery and bulb arrangements.” A drawing’s line length is not automatically a measured physical variable. Recognising missing information is better than inventing a cause.

Choose a connector that matches the relationship

Because introduces a reason. Therefore introduces the result of a reason already stated. Whereas contrasts two arrangements. Unless introduces a necessary change or condition. Have the child read the complete sentence aloud. If switching connectors reverses the meaning, the connector is doing important work.

Try this pair: “The shared switch is open; therefore, neither bulb lights.” Then write: “Neither bulb lights because the shared switch is open.” Both sentences can express the same causal relationship. The order of the information changes, but the scientific claim stays stable.

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Use these questions after the child has explored the relevant groups. They are a learning check, not a timed examination or a prediction of what a school will ask. For every answer, ask which detail makes it correct.

1. Choose the more precise sentence: A: “A closed circuit always makes anything work.” B: “A suitable energy source and working components can operate when their required conducting path is complete.” Answer: B. It includes the conditions instead of making an unlimited claim.
2. Complete the sentence: “The metal inside the wire is a conductor, _____ its plastic covering is an insulator in the conditions discussed.” Answer: whereas. The sentence contrasts the roles of two materials.
3. A test bulb remains unlit when a sample is inserted. What should be checked before concluding that the sample is an insulator? Answer: Check that the circuit works with an appropriate known conductor and that the cell, bulb and contacts are functioning. A dark bulb has more than one possible cause.
4. Two bulbs are drawn side by side. Does this prove they are connected in parallel? Answer: No. Trace whether they lie on separate branches between the same connection points. Their positions on the page do not establish the arrangement.
5. Replace the inaccurate phrase: “The bulb uses up the current.” Answer: “The bulb uses electrical energy to produce light and heat its surroundings.” Current and energy are different ideas, so changing only the adjective would not repair the original claim.
6. What must remain unchanged when comparing one bulb with two identical bulbs in series? Answer: Keep the suitable battery arrangement and other relevant conditions the same, using the same bulb type. Otherwise the result may be affected by more than the intended change.

Mark the explanations as well as the selected words. A child who chooses whereas by chance needs a different next step from a child who can explain the contrast but misspells it. Treat the check as information about the next lesson.

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Rebuild the foundation

If the child confuses the parts or uses “electricity” for every idea, begin with cell, bulb, wire, switch and circuit. Use a printed school diagram. Let the child point, name and explain one function at a time. Add open, closed, gap and complete only when the parts are secure. An accurate spoken explanation is useful progress even before the child can write it independently.

Keep the first written task small: one observation followed by one reason. Provide the first half of the sentence if needed. “The bulb does not light because…” invites a causal explanation without requiring a full paragraph. Remove that support gradually when the child can choose the relevant cause.

Maintain accuracy and transfer

If definitions are secure but answers remain inconsistent, change the context. Rotate the diagram, move the switch, or supply a short passage instead of a picture. Ask which features changed and which did not. Use trace, evidence, whereas and unchanged to make the reasoning explicit.

Review one corrected answer from school. Ask the child to explain the correction in their own words and then solve a related example with a different arrangement. Copying the model answer shows that the child can copy; explaining the change shows more about understanding.

Extend with conditions and counterexamples

If the child can explain ordinary examples independently, introduce a plausible claim and ask for its limit. “If one bulb goes out, the other always remains lit in a parallel circuit.” What if the failure is in a shared connection? The aim is thoughtful precision, not racing ahead into equations that the current task does not require.

For a child following Foundation Science, use extension selectively and keep school expectations central. The vocabulary list is a resource, not a requirement to complete every group at the same speed. A smaller set used accurately is more useful than 100 definitions recited without understanding.

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This suggested routine keeps the task small enough to fit around schoolwork. Adjust its pace to the child. Five sessions need not mean five consecutive days, and there is no prize for finishing every word quickly.

1. Session one: name and connect. Choose four or five words from the parts and pathway groups. Find each in a school diagram and explain its role. Finish with one complete sentence about a closed path.
2. Session two: compare meanings. Revisit those words without looking at the list. Add one contrast, such as conductor and insulator. Discuss an example and a counterexample, including the difference between a metal object and an insulating coating.
3. Session three: read and retrieve. Read the original passage in this guide. Ask two questions orally. Let the child return to the passage to identify the evidence, then close it and explain the answer again.
4. Session four: repair an answer. Choose one sentence from the repair section or an appropriate correction from school. Identify whether its difficulty concerns vocabulary, connections, evidence or grammar. Rewrite only what needs repair.
5. Session five: transfer and choose. Use a new diagram from the child’s existing materials. Ask for a prediction, reason and condition. Decide which words are ready for occasional review and which need another concrete example.

A simple record can have three columns: “I recognise it”, “I can explain it”, and “I can use it accurately”. The columns describe different stages of learning. Move a word only when the child demonstrates the relevant skill in a fresh example, rather than after repeating a memorised sentence.

Keep practical work within appropriate supervision and equipment instructions. The activities on this page can all be completed using text and diagrams. Do not use household sockets, appliance wiring, loose mains connections or improvised short circuits. If a child notices damaged electrical equipment, the useful action is to stop, avoid handling it and tell a responsible adult. Singapore's Energy Market Authority electrical-safety guidance provides the adult reference for household electrical concerns.

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Must my child memorise all 100 words?

No. This is a teaching collection, not a compulsory examination list. Use it to find the words that help with the child's current work. A child who knows the meaning but cannot use it in a new sentence needs practice in application; another who cannot recognise it needs a clear example first.

Why are words such as “if” and “because” included?

They carry the condition and the reason. In science, a missing condition can turn a correct statement into an overgeneralisation. In English, an unsuitable connector can change the relationship between ideas. These small words deserve deliberate practice alongside technical nouns.

Should we learn current direction or electrical equations now?

Follow the child's school syllabus and teaching sequence. The central work here is to identify components, trace paths, compare appropriate arrangements and explain observations. Adding advanced detail before these ideas are secure can make an otherwise manageable task harder to understand.

What if my child gives the right answer using ordinary words?

First check that the meaning is accurate. Then introduce the precise word as a useful name for the idea the child already understands. For example, “the plastic part that stops a conducting connection here” can lead naturally to insulator. The new word should make the explanation shorter and clearer.

What should we do after a wrong prediction?

Separate the prediction, the actual observation and the explanation. Check whether the stated conditions were met. A wrong prediction may reveal a misunderstanding, but an unexpected result may also reveal a faulty connection or an uncontrolled change. The next step is careful checking, not blame.

What is a useful sign of progress?

Look for a child who can explain why a word fits, locate the relevant evidence and adapt the explanation when one condition changes. That is the purpose of this vocabulary work: clearer language that helps the learner return to a diagram, a passage or a classroom question with greater understanding.

For a broader bank covering several topics, continue to Top 200 Vocabulary for Primary 5 Science. Use that collection to explore more science terms, and return to this guide when the next task is reading a circuit explanation, choosing a precise word or improving a written answer.

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