Nature and meaning of science

Correct answer: B. Developing a purification method for clean water

Water purification is a practical application of scientific knowledge. Science solves real problems in society.

Correct answer: C. A trend of increase in a quantity

An upward line generally shows an increasing trend in a quantity. Read the axes before drawing a conclusion.

Correct answer: D. It becomes difficult to know what the data represent

A heading tells what kind of information a table contains. Every table should have a clear heading.

Correct answer: A. Clearly state the object and factor to be measured

The direct answer is option A: clearly state the object and the factor to be measured. A specific scientific question tells us what is being studied and which variable or factor will be observed or measured. It should be clear enough that someone can plan a fair investigation and know what data to collect. For example, asking how the amount of light affects the height of a plant is more specific than asking whether light is good. Option A is correct because it identifies the subject and the measurable factor. Option B is wrong because difficult words can make a question confusing without making it precise. Option C is wrong because placing the answer in the question removes the need for investigation and introduces bias. Option D is wrong because removing evidence makes the question impossible or weaker to test. Memory cue: a strong scientific question names “what” and “which factor,” and avoids vague words such as “better” unless they are defined.

Correct answer: B. Using clear and exact words

The direct answer is option B: using clear and exact words. Precision in scientific language means that the reader understands one definite meaning rather than having to guess. A precise statement identifies the object, condition, quantity, comparison, or time when these matter. For instance, “the temperature rose by 5 °C in ten minutes” is more precise than “it became much hotter.” Option A is wrong because extra words may increase length without increasing clarity. Option B is correct because exact wording reduces misunderstanding and makes observations and conclusions easier to compare. Option C is wrong because precision does not depend on using English; a clear statement in any suitable language can be precise. Option D is wrong because attractiveness or decoration does not make a scientific statement accurate. Precision is about meaning, not appearance. Exam cue: replace vague words such as “large,” “soon,” or “better” with a measurement or a clearly defined comparison whenever possible.

Correct answer: C. To form an unbiased conclusion

Analysing all data helps form an unbiased conclusion. Selecting only convenient data is incorrect.

Correct answer: D. It may be less reliable

The direct answer is option D: it may be less reliable. Data are the observations or measurements used to support a conclusion. If too little data are collected, random variation, an unusual trial, measurement error, or an unexamined condition may strongly affect the result. Therefore the conclusion may not apply broadly and should be expressed cautiously. Option A is wrong because insufficient data cannot guarantee a complete conclusion. Option B is wrong because a conclusion does not automatically become evidence merely by being written; evidence must come from suitable observations or measurements. Option C is wrong because a small amount of data cannot show that the conclusion is correct in every condition. Option D is correct because more adequate and repeated data generally provide stronger support, while insufficient data weaken confidence. A useful cue is: ask whether the sample, number of trials, and measurements are enough before making a broad conclusion.

Correct answer: A. Previous data and evidence

A scientific prediction is based on previous data and evidence. Keep it distinct from an ordinary guess.

Correct answer: B. It is always larger than the real object

A model simplifies reality so some details may be omitted. Do not treat a model as a complete copy of the real object.

Correct answer: C. The strength of available evidence

Among different explanations the one supported by stronger evidence is more acceptable. Personal fame is not decisive.

Correct answer: D. Explaining the conditions under which the results apply

A limitation shows how far a conclusion can be applied. Stating limitations reflects scientific honesty.

Correct answer: A. To protect the eyes from harmful splashes

Safety goggles protect the eyes from chemicals or particles. Always give priority to laboratory safety.

Correct answer: B. Scientific safety

Washing hands after an experiment protects against harmful substances. Safety rules are part of every experiment.

Correct answer: C. To identify substances correctly

Labels help identify substances correctly and use them safely. Do not use an unlabelled substance.

Correct answer: D. To protect health and the environment

The direct answer is option D: proper waste disposal protects health and the environment. Scientific investigations may produce broken glass, sharp objects, chemicals, biological material, or ordinary waste. If such material is left carelessly, it can injure people, cause poisoning or infection, pollute soil and water, or harm plants and animals. The reasoning is: identify the waste; follow the laboratory or school instructions; separate hazardous and ordinary waste; place each type in its correct container; clean the work area safely. Option A is wrong because disposal rules are not meant to make an experiment last longer. Option B is wrong because disposal does not aim to reduce the number of instruments. Option C is wrong because waste disposal must never hide data or results. Option D is correct because safety and environmental protection are its main purposes. Memory cue: safe science protects people, places, and living things.

Correct answer: A. By providing evidence-based information

Science provides evidence-based information that supports more rational decisions. Look for reliable sources in social decisions.

Correct answer: B. A reviewed scientific publication

A reviewed scientific publication is based on evidence and expert examination. Check the reliability of sources.

Correct answer: C. Check the source and evidence

Before accepting online information check its source and evidence. Popularity does not guarantee reliability.

Correct answer: D. Science provides knowledge and technology can apply it

Science provides understanding of the natural world and technology can apply that knowledge. They support each other.

Correct answer: A. Improvement in disease diagnosis and treatment

Scientific achievements can improve healthcare and treatment. Remember social applications of science with examples.

Correct answer: B. Divide tasks and share results

Collaboration requires proper division of tasks and sharing of information. The team should have a common aim.

Correct answer: C. Scientific communication

The direct answer is C: scientific communication. Science is not complete when a result is merely obtained; the result must also be shared clearly so that others can understand, discuss, check, or repeat the work. Explaining an investigation in simple but accurate words is communication. The reasoning is direct: a result has been produced, the student puts its meaning into words, and this transfer of information is scientific communication. Option A, measurement skill, means obtaining a value using an instrument or standard unit; it is not mainly explaining the result. Option B, classification skill, means grouping objects or results according to shared features; no grouping is described here. Option C is correct because clear explanation is communication of scientific evidence. Option D, instrument repair, involves finding and fixing faults in equipment and has nothing to do with expressing a conclusion. Simple language is helpful, but it must remain accurate and should not change the evidence. Exam cue: measuring produces data; explaining or presenting data is communication.

Correct answer: D. New questions and further investigation

The direct answer is option D: scientific inquiry often ends with new questions and further investigation. Science is a continuing process, not a journey that permanently closes every question. After collecting evidence and forming a conclusion, researchers may notice an unexpected result, a limitation, or a related problem. They then ask a new question and design another investigation. The reasoning is: ask a question, investigate it, analyse evidence, draw a conclusion, identify what is still unknown, and begin further inquiry. Option A is wrong because one answer cannot permanently end all scientific questions. Option B is wrong because evidence must be preserved and examined, not destroyed. Option C is wrong because rewards are not the purpose or necessary ending of science. Option D is correct because new knowledge naturally leads to more questions. Memory cue: every scientific answer can open another door.

Correct answer: A. Testing claims through evidence and investigation

Science tests claims through evidence and investigation. This enables it to build reliable knowledge.

Correct answer: B. An organised process of understanding the natural world through evidence and reasoning

Science is a systematic process of understanding the natural world through evidence and reasoning. Remember both process and evidence in the definition.