Scientific questions and observations

Correct answer: B. Weigh it using a balance

To find the mass of a stone, it should be weighed using a balance. A balance is the appropriate instrument for measuring mass. A thermometer measures temperature and a stopwatch measures time, so neither can measure mass. Exam tip: Match the quantity asked—such as mass, time, or temperature—with the correct measuring instrument.

Correct answer: A. The lemon is sour

Whether a lemon is sour is determined using the sense of taste, so option A is correct. Its yellow colour is observed with the eyes, whereas mass and width are measured using instruments. Exam tip: qualities such as sour, sweet, salty and bitter are related to the sense of taste.

Correct answer: A. To clarify the meaning of the measurement

Direct answer: Option A, to clarify the meaning of the measurement. A number alone is incomplete because its meaning depends on the unit. For example, “5” could mean 5 centimetres, 5 metres, or 5 kilograms. The unit tells what kind of quantity was measured and its scale. Therefore a proper observation records both the numerical value and the suitable unit, such as 5 cm. Option A is correct because the unit makes the result understandable and comparable. Option B is wrong because a unit cannot change an object’s colour. Option C is wrong because units make evidence clearer, not hidden. Option D is wrong because writing a unit does not end a question; it completes the measurement. Exam cue: never leave a measured number without its unit.

Correct answer: B. At what time of day do squirrels search for food most often?

The direct answer is B: at what time of day do squirrels search for food most often? A scientific question about animal behaviour must refer to an observable and recordable action under a defined condition. Option B gives an animal, a behaviour—searching for food—and a condition to record—the time of day. An investigator could observe squirrels at regular times, count their food-searching activity, record the data, and compare the counts. Option A is wrong because “cutest” is a personal opinion and cannot be measured by one objective rule. Option B is correct because it can be tested using repeated observations. Option C is wrong because “lucky” is a belief, not a directly measurable behaviour. Option D is wrong because “best friend” is subjective and does not specify observable evidence. Scientific questions can study patterns, frequency, time, and conditions, but they should avoid unsupported personal judgments. Memory cue: good behaviour questions ask what an animal does, when, where, or how often.

Correct answer: A. Record the observation in clear language and include measurements with their units

A scientific observation should be clear, objective, and verifiable. Therefore, it should state what was observed, the measurement, and its unit in clear language. Writing only a conclusion does not allow another person to check the original observation. Exam tip: words such as “clear,” “measurable,” and “with units” usually indicate good scientific recording.

Correct answer: B. Quantitative data

The direct answer is B: quantitative data. Quantitative data are expressed as numbers or counts, while qualitative data describe qualities using words such as colour, texture, or smell. Step by step: the student observes the plant; counts its leaves; writes a numerical value, such as 8 or 15; and can compare that value between plants or over time. Option B is correct because the number of leaves is a count and therefore numerical data. Option A is wrong because qualitative data describe characteristics rather than how many items there are. Option C is wrong because a leaf count is an observation, not a personal opinion. Option D is wrong because the count comes from a real plant and is not invented. Note that counted whole items are quantitative even when the number is not measured with a ruler.

Correct answer: A. Observations and measurements should be recorded

Before writing an experimental result, observations and measurements must be recorded carefully. A result is based on actual data, not on guesses or a preferred conclusion. Assuming that the hypothesis is correct is incorrect because an experiment is used to test it with evidence. Exam tip: Words such as ‘observations’, ‘measurements’, and ‘data’ indicate the scientific method.

Correct answer: B. How does the distance between a magnet and an iron object affect magnetic attraction?

Option B is a scientific question because the distance can be varied and the resulting change in magnetic attraction can be observed or measured. Options A and D are based on personal preference, while option C is based on belief, so they cannot be tested scientifically. Exam tip: Choose questions that can be investigated through observation, measurement, or experiment.

Correct answer: A. The instrument and method should be checked

The direct answer is A: check the instrument and the method. Repeated measurements should usually be reasonably similar when the object and conditions have not changed. Very different readings may result from a faulty or unsuitable instrument, different reading positions, incorrect procedure, changing conditions, or recording mistakes. First inspect the instrument, its zero or calibration, the units, and the method; then repeat the measurement carefully and record all valid readings. Option A is correct because checking can locate the source of disagreement. Option B is wrong because choosing a favourite value introduces bias. Option C is wrong because deleting all values hides evidence. Option D is wrong because a conclusion should not be written before the problem is investigated. Rechecking is not failure; it is responsible scientific practice. Memory cue: unusual data means check, not choose.

Correct answer: A. Date and time when the sprout appears

Recording the date and time when a sprout appears shows how long the seed took to germinate. This is a useful scientific observation for comparing germination progress. The colour of the pot does not measure the germination process. Exam tip: Choose information that is directly related to the process being observed.

Correct answer: A. By stating clear variables and measurable outcomes

A good scientific question clearly identifies the variables to be investigated and allows the outcome to be measured or observed. Therefore, stating clear variables and measurable outcomes makes the question focused, objective, and testable. Words such as “good” and “bad” are vague because they do not give a fixed measure. Exam tip: identify what will be changed and what will be measured in the question.

Correct answer: C. The plant has twelve leaves

‘The plant has twelve leaves’ gives a counted number of leaves, so it is a quantitative observation. The other options describe qualities—cold, yellow, and moist—without giving a count. Exam tip: An observation involving a number, measurement, or amount is generally quantitative.

Correct answer: A. To measure change over a fixed period

The direct answer is A: a time period is stated to measure change over a fixed period. Without a defined duration, two growth results may not be comparable because one may have been observed for longer. Step by step: choose a starting time; choose an ending time or duration; keep relevant conditions consistent; measure the quantity at the start and end, or at regular intervals; compare the change. Option A is correct because time gives the investigation a clear measurement window. Option B is wrong because the purpose is precision, not difficulty. Option C is wrong because a time period clarifies the question rather than hiding its answer. Option D is wrong because stating time does not itself change an object's colour. For example, “How much does the plant grow in 14 days?” is more testable than “How much does it grow?” Exam cue: a fixed interval makes fair comparison possible.

Correct answer: A. By carefully touching and describing it

The direct answer is A: carefully touch the object and describe it. Texture means how a surface feels, for example rough, smooth, soft, hard, or sticky. If the object is safe to touch, use the sense of touch gently and describe the surface using clear words. Safety comes first: do not touch unknown, hot, sharp, corrosive, or dangerous objects; use an appropriate safe method instead. Option A is correct because touch provides direct information about texture. Option B, a thermometer, measures temperature, not surface feel. Option C, a stopwatch, measures time, not texture. Option D is wrong because mass tells how much matter an object has and does not tell whether its surface is rough or smooth. A description can be qualitative, while mass is numerical. Exam cue: texture is mainly linked with touch, but safe observation is always essential.

Correct answer: A. To draw a correct conclusion

Honest recording keeps the conclusion based on real evidence. Recognise scientific objectivity.

Correct answer: B. How does the amount of water affect a plant's height over seven days?

Option B states a measurable outcome, “plant height,” and gives a fixed time period of “seven days.” The water amount can be varied, while height can be measured in centimetres and compared. In options A and C, words such as “good” and “like” do not identify a clear measurable result. Exam tip: Look for the quantity to be measured and a stated time period in a scientific question.

Correct answer: A. It shows when the observation occurred

The date helps track sequence and change over time. Remember the importance of contextual details.

Correct answer: A. An inference may be an explanation based on observation

Observation provides facts and inference suggests their possible meaning. Understand them as distinct but related.

Correct answer: A. Observations can generate questions and questions guide new observations

The direct answer is A. Scientific inquiry is a continuing cycle: an observation may reveal something surprising, that observation creates a question, and the question guides further observations or tests. For example, noticing that one plant grows faster can lead to asking whether light affects growth; then observations are planned to compare light and growth. Option A is correct because it describes this two-way relationship. Option B is wrong: questions and observations are connected, not always separate. Option C is wrong: questions can arise before an answer, and answers are sought because questions exist. Option D is wrong because observations provide evidence and are essential in science. Memory cue: observe, ask, test, conclude, and observe again.

Correct answer: A. Evidence

A scientific question is tested using evidence obtained through observations, experiments, and measurements. Evidence consists of facts or data that can be checked and repeated. Imagination may help form a question, but it cannot establish whether the question is correct. Exam tip: In scientific investigations, choose the option based on testable evidence or data.

Correct answer: C. A fact obtained carefully

The direct answer is C: a carefully obtained fact. A scientific observation is information gathered by using the senses or suitable instruments in a planned, careful way. It should be describable, recordable, and, as far as possible, checkable by another person. Step by step: look at or measure the event; record what was actually detected; avoid adding a personal feeling or unsupported explanation; repeat or compare observations when needed. Option C is correct because it is based on evidence collected carefully. Option A is wrong because a guess without looking has no observation evidence. Option B is wrong because a personal opinion expresses preference, not a measured fact. Option D is wrong because an invented answer has no real evidence. For example, “the liquid temperature was 30 °C” is an observation when measured, while “the liquid looks lucky” is not. Memory cue: observe first, interpret later.

Correct answer: D. The plant is 30 cm tall

A quantitative observation describes a feature using a number and a unit of measurement. In option D, the plant’s height has been measured as 30 cm, so it is quantitative. Saying that a flower is fragrant, a leaf is smooth, or a stone is hard is qualitative because no numerical measurement is given. Exam tip: An observation with a number and a unit such as cm, g, °C, or mL is usually quantitative.

Correct answer: D. Measuring cylinder

A measuring cylinder has graduations for measuring the volume of a liquid, so option D is correct. A balance measures mass, not volume. For an accurate reading, view the bottom of the liquid meniscus at eye level. Exam tip: identify a measuring cylinder as the instrument used to measure liquid volume.

Correct answer: A. Through observation or experiment

The direct answer is A: through observation or experiment. A scientific question is answered by collecting evidence rather than by preference, rumour, or an unsupported story. Observation means carefully watching or measuring something without deliberately changing the tested condition. An experiment means changing a selected factor and observing the resulting effect while controlling other important factors. Step by step: ask a clear question, decide what evidence is needed, observe or perform a fair experiment, record results, and use those results to form a conclusion. Option A is correct because both methods can produce evidence. Option B is wrong because a story alone may be interesting but does not necessarily provide tested evidence. Option C is wrong because personal preference is not proof. Option D is wrong because a rumour is unverified information. Scientific evidence should be repeatable, carefully recorded, and open to checking. Memory cue: science asks, tests, records, and concludes; it does not simply guess.

Correct answer: B. To reduce the chance of forgetting or altering details

Recording an observation immediately captures details such as time, colour, changes, or measurements before memory fades. Therefore, it reduces the chance of forgetting or unintentionally altering details. Stopping an experiment or changing a result is not the purpose of scientific observation. Exam tip: When recording observations, note the time, measurements, and visible changes.