G2 Science is Science studied at General 2 subject level in Singapore’s secondary schools. Bubbles show that a gas or vapour region is present within a liquid or at its surface. They do not, by themselves, prove that a chemical reaction has made a new gas. Boiling, release of dissolved gas, trapped air and chemical gas production can all create bubbles under different conditions.
The quick reasoning is to separate observation from explanation. “Bubbles appeared” is an observation. “Carbon dioxide was produced by a reaction” is a stronger claim requiring suitable evidence about the materials, conditions and gas identity. The correct explanation follows from the whole setup, not the visual cue alone.
This guide focuses on that one decision. It links to the existing physical and chemical change overview for the broader classification topic. Here we compare several bubble mechanisms, read original datasets and show why a gas volume or a falling mass can still need careful interpretation.
These are paper based teaching examples, not instructions to mix unknown materials, heat sealed containers or test gases independently. Practical work belongs under the school’s supervision. Your actual G2 course and Science combination determine required depth; the later measurement examples are useful extensions rather than a promise of identical examination requirements.
Find your next learning step
Read from the beginning, or choose the question closest to your child’s learning needs.
Identify possible bubble mechanisms · Chapters 1–5
Check gas identity and origin · Chapters 6–10
Measure amounts and rates · Chapters 11–15
Evaluate the process evidence · Chapters 16–20
Review and enquire · Chapters 21–25
Contents
Identify possible bubble mechanisms · Chapters 1–5
Check gas identity and origin · Chapters 6–10
Measure amounts and rates · Chapters 11–15
Evaluate the process evidence · Chapters 16–20
Review and enquire · Chapters 21–25
CHAPTER 1 OF 25
1. Describe what is actually visible
A useful observation names the visible change without adding an untested cause. Bubbles form on the container wall, bubbles rise through the liquid, or a foam layer persists at the surface are different descriptions. Each can help interpret the setup, but none alone identifies the gas or mechanism conclusively.
Avoid beginning with “The liquid reacts” when the only supplied evidence is bubbling. That sentence has already selected a chemical explanation. Start with the visible pattern, then ask what additional information supports one cause over another. This keeps the evidence account open long enough to be checked.
Location and timing can matter. Bubbles appearing immediately after pouring may have a different likely explanation from sustained gas collection after specified reactants are combined. A heated liquid can show small bubbles before its main boiling behaviour begins. Read the sequence rather than grouping all bubbling into one event.
The aim is not to make every observation uncertain. It is to give each statement the right status. A clear observation can be definite while its explanation remains underdetermined. That distinction is a practical Science skill, not a reason to avoid answering the question.
CHAPTER 2 OF 25
2. Name the candidate mechanisms
Boiling produces vapour of the liquid within the liquid under suitable pressure and temperature conditions. Dissolved gas can leave a solution when conditions change. Air can be introduced mechanically or escape from pores. A chemical reaction can produce a gas as a new substance.
These mechanisms can sometimes occur together. Heating a gas containing liquid can release dissolved gas before or during boiling. A reacting mixture can also warm, and a foaming liquid can trap gas from another process. Do not assume one visible event must have only one possible contribution.
For a school problem, the materials and conditions usually narrow the intended explanation. Use them. A known carbonate and acid reaction with a suitable gas test is different evidence from a beaker of water warmed without added reactants. The word bubbles is shared, while the account differs.
Make a short set of possibilities mentally before deciding. Ask whether the gas was already present, introduced from outside, produced by a phase change or formed chemically. This is a more dependable route than memorising that one surface appearance belongs permanently to one process.
CHAPTER 3 OF 25
3. Explain boiling as a phase change
During boiling, vapour bubbles can form within a liquid when the relevant conditions allow them to persist and grow. The vapour is the gaseous form of the liquid substance in the simple pure liquid model. A change of state is not automatically a change in chemical identity.
For water boiling under stated ordinary pressure conditions, the main vapour bubbles are water vapour, not bubbles made by splitting water into hydrogen and oxygen. The molecules change physical state without the school model requiring decomposition into their constituent elements.
The boiling temperature depends on pressure and substance identity. Do not attach one universal temperature to every liquid or every pressure setting. Use the supplied conditions. The heating and state change guide explains the wider thermal account.
An observation of bubbles alone cannot establish the entire boiling model. Temperature behaviour, pressure conditions and material identity provide the context. A strong answer connects those conditions with vapour formation rather than declaring every bubbling liquid to be boiling.
CHAPTER 4 OF 25
4. Explain why early heating bubbles can differ
Water and other liquids can contain dissolved gases. As conditions change during warming, some dissolved gas may leave the solution and form visible bubbles. Such bubbles can appear before the liquid reaches the boiling condition relevant to the main vapour process.
This means the first small bubbles on a heated container are not automatically evidence that the whole liquid is boiling. Their composition and cause can differ from the larger sustained vapour bubbles of the intended boiling model. The full sequence and temperature data matter.
Do not turn the correction into another absolute claim that every early bubble must be air. Surface conditions and the experiment can be more complicated. The useful conclusion is narrower: bubbling before a stated boiling condition does not by itself prove boiling or a new chemical gas.
If a question supplies a temperature curve and bubble observations, align them in time. Ask when the observation occurred relative to the measured conditions. The graph can help distinguish candidate explanations, while the bubble description alone leaves more possibilities open.
CHAPTER 5 OF 25
5. Explain dissolved gas release without making new gas
A liquid can contain gas dissolved under its preparation conditions. If pressure or temperature changes, the equilibrium dissolved amount can change and gas can leave solution. The appearance of bubbles then need not mean that a new gas substance was chemically created.
A carbonated drink provides a familiar example. Opening changes the gas pressure conditions above the liquid, and dissolved carbon dioxide can leave. The existing fizzy drink guide explains that system in more detail. Here its role is to show why gas identity alone does not establish the formation mechanism.
Even if the escaping gas is identified as carbon dioxide, it may have been present beforehand in dissolved form. “Carbon dioxide is present” and “Carbon dioxide has just been made by this reaction” are separate claims. A suitable before and after account is needed for the second.
The dissolving rate and solubility guide supplies the wider equilibrium distinction. A change in where a substance is located can create a visible effect without changing that substance into a new chemical identity.
CHAPTER 6 OF 25
6. Explain mechanically introduced air
Pouring, shaking or stirring can introduce air into a liquid. Bubbles may then rise or remain trapped by the liquid’s properties. The visible gas can come from the surroundings rather than from a reaction between the liquid’s components.
An object placed in a liquid may also release air from surface pockets or pores. A few bubbles around it do not automatically prove that its material reacts with the liquid. The object may simply carry gas into the container and release it as the liquid enters accessible spaces.
The setup determines whether this is a plausible alternative. A supplied model may explicitly exclude trapped air or provide sustained gas production evidence that goes beyond a brief initial release. Use those details rather than treating all alternative explanations as equally likely in every question.
A useful answer distinguishes initial and continuing behaviour. “Some early bubbles could be displaced air” is a limited possibility, not proof that all later collected gas has that source. The student should match the explanation to the timing and amount supported by the data.
CHAPTER 7 OF 25
7. Separate foam stability from gas production rate
Foam is a collection of gas bubbles separated by liquid films. Its height can depend on how well those films persist as well as how much gas enters them. A tall foam layer does not necessarily measure a higher instantaneous gas production rate.
Two liquids receiving the same gas volume can produce different foam heights if their bubble sizes and film stability differ. Conversely, a process can produce substantial gas without a lasting foam layer if bubbles burst readily. The visible surface pattern is not a universal calibrated gas meter.
If a school investigation uses foam height as a proxy, its limitations should be stated and relevant conditions controlled. Do not label a centimetre foam reading as a gas volume in cubic centimetres without a defined relationship. The unit itself shows the difference between height and amount.
This is the same measurement discipline used in the potometer guide. An accessible indicator can be useful, but the link from indicator to target quantity needs a model. Visibility alone does not provide exact calibration.
CHAPTER 8 OF 25
8. Explain chemical gas formation through substances
A chemical reaction can produce a gas by changing substances through rearrangement of atoms and bonds in the school model. A suitable carbonate reacting with an acid can produce carbon dioxide under stated conditions. The reactants and reaction account provide evidence beyond the fact that bubbles appear.
A complete explanation should identify the relevant substances and, where required, a word or balanced equation. The equation is not merely a decorative label. It states the chemical transformation that supports calling the gas a product rather than an already dissolved component leaving the liquid.
Do not assume every solid plus liquid combination follows the same reaction. A soluble solid might dissolve, a porous solid might release air, and another solid might react. Read the identities and conditions instead of matching the container arrangement to a memorised chemical pattern.
The guide to tracking matter through equations develops the later atom account. Here the core question is simpler: what evidence shows a new substance formed, rather than only a physical relocation or phase change of something already present?
CHAPTER 9 OF 25
9. Use gas identity as one part of the evidence
A suitable gas identification result can narrow what gas is present. In school contexts, named tests and observations may be supplied. Interpret those according to the course and method. The identity result still needs to be connected to the starting materials and conditions before a formation mechanism is concluded.
For example, evidence for carbon dioxide can fit a carbonate acid reaction or release from a carbonated solution. The same identified gas can arise through different routes. A test answers an identity question; the full experimental account answers where that gas came from.
An incomplete or unsuitable test can also leave ambiguity. A negative result may reflect a method limitation rather than proof that no gas exists. Use the stated controls and observations rather than turning a single colour or flame description into a universal explanation of every gas sample.
This guide does not provide independent gas testing instructions. Actual tests can involve chemicals or ignition hazards and belong under supervision. The paper based skill is to distinguish what the supplied result establishes from the stronger claims that require additional evidence.
CHAPTER 10 OF 25
10. Keep temperature change separate from proof of reaction
A mixture warming or cooling can support an energy transfer observation, but temperature change alone does not uniquely prove chemical reaction. Dissolution and other physical processes can also involve thermal changes. The material identities and full before and after account remain necessary.
Likewise, heating a liquid does not mean every resulting bubble is a chemical product. Energy input can drive a physical state change or release dissolved gas. The presence of a heater supplies a condition, not an automatic reaction label.
If a reaction is independently established, its temperature change may help describe an exothermic or endothermic account at the required level. But the reasoning should not be reversed into “It got warmer, therefore a new substance definitely formed” without considering alternatives.
This chapter reinforces the observation explanation split. Temperature, colour and bubbles are useful clues, especially together with known substances and appropriate tests. They become misleading when any one clue is treated as an infallible shortcut that replaces the actual chemical evidence.
CHAPTER 11 OF 25
11. Read mass loss using an open system boundary
If gas leaves an open container, the measured mass of what remains can decrease. That observation does not mean matter has been destroyed. The balance is measuring a particular system boundary, while some material has crossed that boundary into the surroundings.
Mass loss can arise from evaporation, escape of previously dissolved gas or chemical gas production. The balance reading alone does not identify which mechanism occurred. The same numerical pattern can fit different physical accounts, so the materials and conditions still matter.
In a supplied reaction experiment, a falling mass can be used to track gas leaving under suitable assumptions. State what other losses are controlled or neglected. Liquid splashing or solvent evaporation could otherwise contribute to the measured change and weaken the interpretation.
The useful routine is to name the weighed contents, identify what can enter or leave and account for the change. “The mass fell” is an observation. “A certain amount of reaction gas escaped” is an interpretation that requires the rest of the method to support it.
CHAPTER 12 OF 25
12. Use closed system conservation carefully
In a properly closed ordinary chemical system, total mass is conserved even if gas forms inside. A reaction can occur without the balance reading decreasing because the gas remains within the measured boundary. Visible bubbling and mass conservation are therefore compatible.
Do not infer no reaction merely because total mass stayed constant. The observation may simply reflect a closed boundary. To judge chemical change, examine substance identity evidence rather than expecting a loss that the setup physically prevents.
This is a conceptual model, not advice to heat or react materials in sealed containers. Pressure can build and create hazards. Actual apparatus must follow the teacher’s approved procedure. A paper question can discuss a closed system without authorising an improvised practical version.
When comparing open and closed diagrams, keep the initial contents and measurement boundary clear. The apparent mass outcomes can differ while the underlying conservation principle stays the same. The difference is where the gas ends up relative to what the balance includes.
CHAPTER 13 OF 25
13. Calculate an amount rate only from matched data
Suppose a supplied experiment collects 18 cm³ gas in six seconds over a defined interval. The average collection rate is 3 cm³/s. This is a volume rate under the collection conditions. It does not directly state the number of bubbles or the gas’s chemical identity.
If the gas reading rises from 10 cm³ at four seconds to 34 cm³ at twelve seconds, use the changes: 24 cm³ over eight seconds, again giving 3 cm³/s. Dividing final readings alone would describe a different interval and could produce the wrong comparison.
A faster collected volume rate can indicate faster gas production in a suitable controlled reaction method. It may also be affected by leakage, collection delay or changing temperature and pressure. The measurement model should match the strength of the conclusion.
The reaction rate versus final amount guide develops the broader graph distinction. Here the additional caution is that the gas must first be attributed to the process being studied before its collection rate becomes evidence for that process’s rate.
CHAPTER 14 OF 25
14. Explain why bubble count can mislead
Counting bubbles per minute can provide a rough indicator when bubble sizes and conditions are comparable, but equal counts do not guarantee equal gas volumes. Ten large bubbles can contain more gas than twenty small ones. The count is not automatically an amount measurement.
Bubble merging, breakup and film behaviour can change the count without changing the underlying total gas transfer in the same proportion. A method that relies on counts should acknowledge this limitation rather than reporting an exact volume rate from an uncalibrated visual tally.
If a question provides a fixed volume per bubble as a model assumption, use it. For example, twelve bubbles each representing 0.20 cm³ correspond to 2.4 cm³ under that stated model. Do not import that assumption into a different experiment where bubble volumes are unknown.
This is a good independent check: ask what extra information would let a count become a volume. A learner who requests a bubble volume calibration has identified the missing link, rather than merely refusing the calculation or inventing a convenient value.
CHAPTER 15 OF 25
15. Keep gas temperature and pressure in comparisons
A gas volume depends on temperature and pressure as well as amount. Equal measured volumes under different conditions need not contain equal amounts of gas. A warm sample can occupy a different volume without a reaction producing additional gas particles.
For a fair amount comparison using collected volumes, match or account for the relevant conditions. A school problem may explicitly state that all volumes are measured at the same temperature and pressure. That statement is part of the reasoning, not background wording to ignore.
If one treatment heats the gas collection apparatus more than another, a larger final volume may combine thermal expansion with amount differences. The student should identify which conclusion remains supported and which needs correction or additional measurement.
Do not introduce advanced gas equations unless the course or question requires them. The accessible principle is sufficient: a volume is an amount proxy only under suitable comparable conditions. Naming those conditions prevents a larger visible space from becoming automatic evidence of more chemical product.
CHAPTER 16 OF 25
16. Compare initial bursts with sustained production
An initial burst can come from trapped air, dissolved gas release or a rapid reaction stage. The timing pattern is useful but does not identify one cause uniquely. A method may need a background control or further observations to distinguish the contributions.
Sustained gas collection after a known reaction starts can strengthen a chemical interpretation when other sources are controlled. But sustained release of dissolved gas is also possible under some conditions. Avoid assigning mechanisms solely by whether bubbling lasts a short or long time.
Read the full sequence: preparation, treatment change, initial observation, later measurement and endpoint. A gas volume recorded before the intended reaction begins should not automatically be counted as product. Conversely, a collection delay may miss early product and underestimate total production.
This is a measurement boundary in time as well as space. The student should state when the relevant interval starts and ends. A correct subtraction cannot repair a dataset that includes the wrong stage of the process in the first place.
CHAPTER 17 OF 25
17. Use a background comparison for the actual question
A comparison without the proposed gas producing reaction can help assess background effects such as warming, stirring or dissolved gas release. The appropriate control depends on the hypothesis. It should reproduce relevant conditions while removing or changing the factor whose role is being tested.
Do not assume one universal control works for every setup. Removing a solid might also remove a rough nucleation surface or change mixing. A useful evaluation identifies what differs and whether that difference introduces another explanation. The control should be chosen for the causal question, not copied from a previous experiment.
If both treatment and control bubble on warming, the observation weakens a claim that bubbling alone uniquely identifies reaction in the treatment. It does not necessarily prove no reaction occurred there. Several processes can contribute simultaneously, so further evidence may still be needed.
State the limited conclusion clearly. “Some bubbling can occur without the proposed reaction” follows from a suitable control. “All treatment gas must have that background source” requires more. Good controls narrow possibilities, but they do not automatically answer every quantitative attribution question.
CHAPTER 18 OF 25
18. Separate a plateau from proof of complete reaction
A collected gas graph becoming flat means the recorded volume is no longer increasing detectably over that interval. In a suitable reaction model, that may indicate completion because a limiting reactant is used up. Other explanations can include a leak, blockage, equilibrium or measurement limits, depending on the setup.
Use the supplied evidence to select the intended interpretation. A clear school question may state complete reaction and ideal collection. Under those assumptions, the plateau can support a final amount. In an evaluation, the same shape should not be treated as unique proof without considering the method.
For dissolved gas release, a plateau can indicate approach to the new equilibrium condition rather than chemical reactant exhaustion. For boiling, a collection plateau may reflect a changed heat supply or apparatus condition. The graph’s shape does not identify the process by itself.
This is why the article begins with mechanisms rather than equations. A graph summarises measurements, while a model explains them. The strongest answer connects both and keeps the assumptions visible instead of assigning a familiar story to every curve with a flat ending.
CHAPTER 19 OF 25
19. Explain reversibility without using it as the definition
A gas leaving a solution can sometimes be redissolved under suitable changed conditions, while a chemical process can also be reversible in principle. Reversibility is therefore not a complete definition separating physical and chemical change. The central distinction concerns substance identity.
Likewise, difficulty reversing a change in an ordinary classroom does not prove chemical reaction. Broken glass is physically changed even if it cannot be restored by simply reversing one easy action. A practical inconvenience is different from evidence of new chemical substances.
For a bubble question, ask whether the gas was formed as a new substance or moved from another state or location. The answer may use before and after information, known materials and suitable tests. A reversible label by itself leaves the actual mechanism unexplained.
The existing physical and chemical change guide owns that broader distinction. Here it protects one specific inference: bubbles plus an apparently irreversible appearance are still not a substitute for identifying what happened to the substances.
CHAPTER 20 OF 25
20. Repair four common bubble claims
“Bubbles prove a new gas was made” needs alternative mechanisms considered. Vapour formation, dissolved gas release and introduced air can all produce bubbles without the claimed chemical production. Use the complete setup and supporting tests to establish the mechanism.
“Carbon dioxide proves an acid carbonate reaction” confuses gas identity with origin. Carbon dioxide can already be dissolved in a liquid. A suitable reaction account needs the starting materials and before and after evidence, not only the identity of the gas collected.
“More bubbles means a greater gas volume” needs bubble size and time. A count is not automatically a volume, and a volume is not automatically a rate. State what was measured and what calibration or matched conditions support the comparison.
“Mass fell, so matter was destroyed” ignores the measurement boundary. Gas or vapour can leave an open weighed system. Account for the material that crossed the boundary before drawing a conclusion about conservation or the type of process.
CHAPTER 21 OF 25
21. Work through three different bubbling situations
Situation A describes a pure liquid reaching its stated boiling condition and producing vapour of that same substance. Under the supplied model, this is a physical state change. The bubbles do not mean the liquid’s molecules have been decomposed into different elements.
Situation B describes a carbonated liquid after its surrounding gas pressure changes, with carbon dioxide leaving solution. The gas can have been present before the observation. Bubbles and a positive carbon dioxide identification do not require a newly occurring acid carbonate reaction.
Situation C specifies a carbonate reacting with an acid, appropriate product evidence and controlled collection. Here a chemical gas product interpretation is supported by the full account. The visible bubbling is one part of the evidence rather than the sole defining feature.
Ask the learner to write one shared observation and three different explanations. That exercise shows why observation and interpretation must be separated. It also makes the article’s main reasoning immediately usable: the same surface cue can belong to different physical or chemical stories.
CHAPTER 22 OF 25
22. Build a lesson around the unsupported leap
A numerical check on what the indicator measures
In an invented model, sample A produces twenty visible bubbles in ten seconds and sample B produces thirty bubbles in the same time. The count rates are two and three bubbles per second. Without bubble volumes, that establishes a count comparison, not a volume comparison or a chemical production mechanism.
Suppose a supplied calibration then states each A bubble represents 0.30 cm³ and each B bubble represents 0.10 cm³ under matched collection conditions. A corresponds to 6 cm³ in ten seconds, or 0.60 cm³/s. B corresponds to 3 cm³ in ten seconds, or 0.30 cm³/s. The sample with the greater bubble count now has the smaller volume rate.
Those calibration values are invented for the exercise, not universal bubble sizes. Their purpose is to expose the missing relationship. A count can become a volume only when a suitable conversion is justified. Even after that conversion, gas identity and origin still need their own evidence.
Consider a further comparison: two containers each lose 1.0 g over a stated interval. One is an evaporation model; the other is a supplied gas producing reaction model. Equal mass losses do not establish equal gas volumes, equal substances or equal reaction rates. The observation is a mass crossing the selected weighed boundary. The physical or chemical interpretation comes from the rest of each setup.
Ask the learner to list what remains unknown after each new measurement. A volume calibration resolves amount per bubble under its assumptions, but not identity. An identity test resolves a species question, but not necessarily whether it was newly formed. This stepwise account turns a vague warning about uncertainty into a practical method for choosing the next useful evidence.
If the student labels every bubble a reaction, begin with boiling and dissolved gas examples before adding equations. If they know the alternatives but cannot choose, inspect the materials and conditions. If measurement fails, separate gas identity, volume, count and rate before calculating.
A focused lesson can present three short descriptions with the same observation and different evidence. Ask what additional fact changes the conclusion. This teaches evidence selection rather than a longer list of exceptions that the learner must memorise without seeing the common logic.
Small group teaching can help when each student proposes an explanation and another identifies the evidence needed to support it. The teacher can then correct a specific inference. A changed example should follow so the learner demonstrates a method rather than recalling one labelled beaker picture.
Parents can look for precise progress: the child says bubbles show gas or vapour is present, asks whether it was already dissolved and distinguishes a gas test from a reaction origin claim. Those are signs of stronger reasoning, not unnecessary hesitation about familiar Science words.
CHAPTER 23 OF 25
23. Try three independent checks
First, a liquid bubbles after vigorous pouring without any other supplied change. Does that establish a reaction? No. Introduced air is a plausible alternative, and more evidence is needed. Do not invent a gas identity from the observation alone.
Second, a supplied collection reading increases from 6 cm³ at two seconds to 26 cm³ at seven seconds. The interval rate is 20 divided by five, giving 4 cm³/s. This is a collection volume rate under the stated conditions, not a bubble count or automatic proof of chemical origin.
Third, two samples produce ten bubbles each, but their bubble volumes are unknown. Can their total gas amounts be ranked from the count alone? No. A suitable volume measurement or size calibration is missing. Equal counts do not guarantee equal volume, especially across different liquids or apparatus.
After answering, add one new piece of evidence: known reactants, matched collection conditions or a gas identity result. Ask exactly which uncertainty it resolves. Independent understanding includes recognising both the value and the limits of each additional observation.
CHAPTER 24 OF 25
24. Answer the questions readers often ask
Can physical and chemical processes occur together? Yes. A reacting mixture can also warm, release dissolved gas or evaporate. A complete account may need several processes. A school model can simplify them, but the student should not assume one visible event excludes every other contribution.
Does a positive gas test prove the mechanism? It supports identity under the stated method. Origin still depends on the starting materials and conditions. The same gas can be released from a solution or produced chemically, so the test answers only part of the question.
Does no bubbling prove no reaction? No. Many reactions do not produce a visible gas, and a gas producing process may not show obvious bubbles under every condition. Absence of one visual cue is not a universal test for absence of chemical change.
Must every G2 student learn all gas measurement extensions here? No. The actual course sets required depth. Start with observation versus explanation and the supplied materials. Add rate, gas condition and control detail where it supports the current syllabus rather than treating this broad guide as a fixed paper outline.
CHAPTER 25 OF 25
25. Choose the next useful learning step
If classification is weak, list the plausible bubble mechanisms before choosing. If claims are too strong, separate observation, identity and origin. If calculations fail, label count, volume, time and measurement conditions. If evaluation is vague, name one alternative cause and the comparison that would test it.
For broader reasoning, visit How Science Works. The OpenStax solubility chapter provides background on dissolved gases, while the state change guide explains the thermal route. Use school instructions for any practical work rather than improvising gas tests.
Keep practice focused: one boiling description, one gas release description and one known reaction account. Ask which evidence distinguishes them. The aim is not to distrust every observation, but to use each observation for the conclusion it can actually support.
For individual support, bring a recent question and the student’s explanation to an eduKate consultation. A useful review identifies the first unsupported leap, repairs it with a contrasting example and checks whether the learner can reason through a new setup independently.
Continue with the Science explanation series
What is G1 Science | Why a Higher Pitch Is Not the Same as a Louder Sound
What is G3 Science | Why an Ionic Solid Conducts When Molten but Not When Its Ions Are Fixed
What is G1/G2/G3 Science | Why a Positive Leaf Starch Test Does Not Give the Photosynthesis Rate