Premium CBSE KV Question Bank Class8 Science Ch1 00

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 2 TABLE OF CONTENTS Student Instructions Section A – Multiple Choice Questions (MCQs) .............. 20 Qs Section B – Very Short Answer Questions .................... 10 Qs Section C – Short Answer Questions – I (2 Marks) ......... 8 Qs Section D – Short Answer Questions – II (3 Marks) ........ 8 Qs Section E – Long Answer Questions (5 Marks) .............. 6 Qs Section F – Competency-Based Questions ................... 8 Qs Section G – Assertion & Reason Questions ................. 6 Qs Section H – Case-Based Questions ......................... 3 Cases Section I – Source-Based Questions ....................... 3 Sets Section J – HOTS (Higher Order Thinking Skills) .......... 6 Qs Prepared By / Credits Difficulty Distribution: Moderate ~70% | Difficult ~30% Total Questions: Approximately 80 high-quality competency-based items

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 3 STUDENT INSTRUCTIONS 1. Read every question carefully before answering. 2. For MCQs, choose the most appropriate option (A/B/C/D). 3. Write answers in clear, concise language using NCERT terminology. 4. For short and long answers, use bullet points where helpful and highlight key terms. 5. Time management: Allocate time according to marks (approx. 1–1.5 min per mark). 6. Assertion–Reason: Select the correct option based on both statements. 7. Case-based and source-based questions test interpretation – read the passage fully. 8. HOTS questions require critical thinking; support answers with scientific reasoning. 9. This question bank follows the latest CBSE 2026–27 competency-based pattern and KVS guidelines. 10. Focus on the spirit of investigation: observation, controlled variables, and systematic enquiry. Bloom's Taxonomy Levels: Remember | Understand | Apply | Analyse | Evaluate | Create

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 4 SECTION A – MULTIPLE CHOICE QUESTIONS (20 Questions) Each question carries 1 mark. Choose the correct option. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Root & Kite Symbolism Q1. In the Curiosity textbook, the image of a root at the bottom of left-hand pages symbolises: (a) Soaring imagination (b) Deep foundation of knowledge connected to environment and heritage (c) Flight of a kite (d) Only traditional knowledge Answer: (b) Deep foundation of knowledge connected to environment and heritage Explanation: The root represents the solid foundation of knowledge that keeps us connected to environment, traditions and heritage. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Root & Kite Symbolism Q2. The kite on the right-hand pages reminds us that: (a) We should only stay grounded (b) Curiosity must take flight to explore the unknown (c) Science needs no creativity (d) Observations are unnecessary Answer: (b) Curiosity must take flight to explore the unknown Explanation: The kite symbolises that curiosity must soar while remaining grounded in careful observation. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Nature of Investigation Q3. Investigation in science means: (a) Only memorising facts (b) Asking focused questions, designing simple experiments and improving understanding from observations (c) Avoiding questions (d) Looking at something without asking questions Answer: (b) Asking focused questions, designing simple experiments and improving understanding from observations Explanation: Grade 8 emphasises becoming investigators who ask focused questions and experiment thoughtfully. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Overview of Journey Q4. According to the chapter, the journey of Grade 8 science begins with examining: (a) Stars and galaxies only (b) Something as small as a single drop of water and tiny organisms (c) Only climate change (d) Only electric current Answer: (b) Something as small as a single drop of water and tiny organisms Explanation: The investigative adventure starts from tiny microbes invisible to the naked eye. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Electricity Overview Q5. The heating effect of electric current is used to: (a) Run motors only (b) Keep us warm (c) Generate magnetic fields only (d) Produce light only Answer: (b) Keep us warm Explanation: The chapter mentions dependence on the heating effect of electric current to keep us warm. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Forces Q6. Understanding forces helps explain why: (a) Sugar dissolves in tea (b) A ball thrown up falls back to the ground or a car stops when brakes are applied (c) The Moon has phases (d) Microbes cause infections Answer: (b) A ball thrown up falls back to the ground or a car stops when brakes are applied Explanation: Forces make objects speed up, slow down or change direction; gravity and friction are examples. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Pressure & Weather Q7. A small difference in air pressure can result in:

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 5 (a) Only cyclones (b) A gentle breeze (c) Only solid particles moving (d) No movement of air Answer: (b) A gentle breeze Explanation: Small pressure difference → gentle breeze; stronger difference → strong winds or cyclones. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Nature of Matter Q8. In solids, particles: (a) Move around freely (b) Cannot move much (c) Are completely absent (d) Only vibrate in gases Answer: (b) Cannot move much Explanation: In solids particles cannot move much; in gases they move freely. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Classification of Matter Q9. Materials can be classified into: (a) Only mixtures (b) Elements, compounds and mixtures (c) Only elements and solutions (d) Only pure substances Answer: (b) Elements, compounds and mixtures Explanation: Elements are pure substances; compounds are bonded elements; mixtures can be separated physically. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Light Q10. Light rays bend when passing through: (a) Only flat mirrors (b) Lenses (c) Only the Moon (d) Only rough surfaces Answer: (b) Lenses Explanation: Light reflects off mirrors and bends (refracts) when passing through lenses. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Moon Phases Q11. The phases of the Moon arise because of: (a) Changes in the Moon’s size (b) Relative positions of the Earth, Moon and Sun (c) Only Earth’s rotation (d) Clouds covering the Moon Answer: (b) Relative positions of the Earth, Moon and Sun Explanation: Different parts of the Moon are illuminated depending on the relative positions of Earth, Moon and Sun. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Calendars & Moon Q12. Watching the periodic cycles of the Moon’s phases allowed humans to create: (a) Microscopes (b) The first calendars (c) Electric motors (d) Vaccines Answer: (b) The first calendars Explanation: Observations of lunar cycles, sunrises and sunsets led to various calendars. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Earth & Life Q13. Earth is ‘just right’ for life mainly because: (a) It is the largest planet (b) It lies at the perfect distance from the Sun so water remains liquid and has a protective atmosphere (c) It has no atmosphere (d) It is closest to the Moon Answer: (b) It lies at the perfect distance from the Sun so water remains liquid and has a protective atmosphere Explanation: Distance allows liquid water; atmosphere provides oxygen and shields from harmful UV rays. Marks: 1 | Difficulty: Moderate | Bloom: Apply | Topic: Scientific Investigation Q14. In the puri investigation, the things we can change or control are called:

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 6 (a) Observations only (b) Variables we control (c) Results only (d) Conclusions Answer: (b) Variables we control Explanation: Thickness of dough, type of flour, oil temperature, way of dropping are controllable variables. Marks: 1 | Difficulty: Moderate | Bloom: Apply | Topic: Controlled Experiments Q15. While doing experiments it is better to: (a) Change many things at the same time (b) Change only one thing at a time while keeping other conditions same (c) Never record observations (d) Avoid questions Answer: (b) Change only one thing at a time while keeping other conditions same Explanation: Changing one variable at a time helps us clearly see the effect of that variable. Marks: 1 | Difficulty: Difficult | Bloom: Evaluate | Topic: Nature of Science Q16. Even the simple everyday observation of a puri puffing is: (a) Completely understood by all scientists (b) Not really completely understood by scientists today (c) Impossible to investigate (d) Unrelated to science Answer: (b) Not really completely understood by scientists today Explanation: The chapter notes that even this simple phenomenon is not fully understood, showing science is still evolving. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Science Everywhere Q17. The kitchen at home is described as: (a) Unsuitable for science (b) A wonderful place to observe and ask questions (c) Only for cooking (d) A place where experiments cannot be done Answer: (b) A wonderful place to observe and ask questions Explanation: Science is everywhere; a fancy laboratory is not always needed for simple experiments. Marks: 1 | Difficulty: Difficult | Bloom: Analyse | Topic: Climate Challenge Q18. Human activities can cause small changes in Earth’s temperature, leading to: (a) No effect on climate (b) Disruption of climate patterns with dangerous consequences (c) Only cooling of the planet (d) Increase in Moon’s size Answer: (b) Disruption of climate patterns with dangerous consequences Explanation: Human influence on climate is highlighted; science must guide protective actions. Marks: 1 | Difficulty: Difficult | Bloom: Analyse | Topic: Scientific Method Q19. What is the correct sequence of the investigative approach described for the puri? (a) Conclusion → Experiment → Question (b) Ask scientific question → Identify variables & observations → Experiment systematically → Record & ask further questions (c) Only observe without questioning (d) Change all variables together Answer: (b) Ask scientific question → Identify variables & observations → Experiment systematically → Record & ask further questions Explanation: This mirrors systematic investigation used in all scientific experiments. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Ecosystems Q20. Ecosystems are formed by: (a) Only non-living things (b) Relationships between living organisms and their environments (air, water, sunlight and other organisms) (c) Only plants (d) Only animals Answer: (b) Relationships between living organisms and their environments (air, water, sunlight and other organisms) Explanation: Every living being depends on and responds to air, water, sunlight and other organisms.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 7

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 8 SECTION B – VERY SHORT ANSWER QUESTIONS (10 Questions) Answer in one word or one sentence. Each carries 1 mark. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Symbolism Q1. What do the root and the kite together invite students to do? Answer: Stay grounded in real observations while allowing ideas to soar towards new horizons. Explanation: Balance careful observation with creative thinking. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Investigation Q2. Name one everyday example of investigation mentioned in the chapter. Answer: Why does dough rise? / Why is one side of a puri thinner than the other? Explanation: Everyday life questions are starting points for scientific investigation. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Electricity Q3. What does the magnetic effect of electric current help in? Answer: It helps motors run and machines function. Explanation: Mentioned as a useful effect of electric current. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Pressure Q4. Define pressure in the context of the chapter. Answer: How the force is distributed over an object. Explanation: Force and pressure concepts also explain air movement. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Solutions Q5. Give one example of a solution mentioned in the chapter. Answer: Sugar dissolving in tea to make it sweet. Explanation: Illustrates how particles mix in solutions. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Light Q6. What do rough surfaces and the Moon do with light? Answer: They reflect light. Explanation: Not only polished mirrors reflect; rough surfaces and the Moon also reflect light. Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Earth Q7. What shields us from harmful ultraviolet rays? Answer: Earth’s atmosphere. Explanation: Atmosphere provides oxygen and UV protection. Marks: 1 | Difficulty: Moderate | Bloom: Apply | Topic: Investigation Q8. In experiments, what should we keep notes of? Answer: Everything that we see and sense (e.g., oil splatters, smell, smoke). Explanation: Recording observations is essential in systematic investigation. Marks: 1 | Difficulty: Moderate | Bloom: Apply | Topic: Variables Q9. Name two things that can be controlled while investigating puri puffing. Answer: Thickness/size of dough, type of flour, oil temperature, way of dropping dough (any two). Explanation: These are controllable variables. Marks: 1 | Difficulty: Difficult | Bloom: Evaluate | Topic: Climate Q10. What is at the heart of both the climate problem and its possible solution? Answer: Us (human beings) – we influence climate and can use science to guide actions. Explanation: Humans are both the cause and the potential solution.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 9 SECTION C – SHORT ANSWER QUESTIONS – I (8 Questions | 2 Marks) Answer in 3–4 lines. Marks: 2 | Difficulty: Moderate | Bloom: Understand | Topic: Symbolism Q1. Why does the textbook use the symbols of root and kite? Model Answer: • The root symbolises deep, solid foundation of knowledge linked to environment, traditions and heritage. • The kite reminds us that curiosity must take flight to explore the unknown. • Together they invite us to stay grounded in observation while letting ideas soar. Marks: 2 | Difficulty: Moderate | Bloom: Understand | Topic: Investigation Q2. What is meant by ‘investigation in science’ in Grade 8? Model Answer: • It means more than looking and asking simple questions. • Students learn to ask focused questions, design simple experiments, observe carefully and improve understanding. • Each student becomes an investigator exploring real-world puzzles. Marks: 2 | Difficulty: Moderate | Bloom: Remember | Topic: Overview Q3. List any three topics that Grade 8 science journey will cover. Model Answer: • Tiny microbes and health (food, exercise, medicines, vaccines) • Electric current, forces, pressure and weather (winds, cyclones) • Particles of matter, classification, solutions, light, Moon phases, ecosystems and Earth’s climate Marks: 2 | Difficulty: Moderate | Bloom: Understand | Topic: Pressure & Weather Q4. How are force and pressure related to weather events? Model Answer: • Force distributed over an area is pressure. • Small air-pressure difference → gentle breeze. • Stronger pressure difference → strong winds and sometimes cyclones that affect daily life and safety. Marks: 2 | Difficulty: Moderate | Bloom: Understand | Topic: Classification Q5. Why is classifying materials into elements, compounds and mixtures important? Model Answer: • Classification is a key feature of science. • Elements are pure substances; compounds are bonded elements; mixtures can be separated physically. • It helps us understand how particles combine or mix (e.g., sugar in tea). Marks: 2 | Difficulty: Moderate | Bloom: Understand | Topic: Moon & Calendars Q6. How did observations of the Moon help humans? Model Answer: • Periodic cycles of Moon phases were carefully observed. • Combined with sunrises and sunsets, these observations led to the first calendars. • Calendars that guide our routines are linked to motions of celestial objects. Marks: 2 | Difficulty: Moderate | Bloom: Understand | Topic: Earth & Life Q7. What makes Earth suitable for life according to the chapter? Model Answer: • Perfect distance from the Sun so that water remains liquid. • Atmosphere that provides oxygen and shields from harmful ultraviolet rays. • These conditions support the complex ecosystems of living organisms. Marks: 2 | Difficulty: Moderate | Bloom: Apply | Topic: Experimental Practice Q8. State two good practices while performing a scientific experiment. Model Answer: • Change only one variable at a time, keeping other conditions the same. • Keep detailed notes of everything observed and sensed (sight, smell, sound, etc.).

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 10 SECTION D – SHORT ANSWER QUESTIONS – II (8 Questions | 3 Marks) Answer in about 5 lines with structured points. Marks: 3 | Difficulty: Moderate | Bloom: Understand | Topic: Progression of Science Learning Q1. Explain how Grade 8 science builds upon Grades 6 and 7. Model Answer: • Grade 6: Science begins with wonder and simple “Why?” and “How?” questions. • Grade 7: Science is always evolving; each answer opens new questions; ideas change as we explore deeper. • Grade 8: Wonder and evolution come together; students learn to investigate – ask focused questions, design experiments and explain observations. Marks: 3 | Difficulty: Moderate | Bloom: Understand | Topic: Electricity Q2. Describe the role of electric current as introduced in the chapter. Model Answer: • Electric current makes lives easier in many ways. • Heating effect keeps us warm. • Magnetic effect helps motors run and machines function. • These phenomena depend on fundamental forces, leading into the study of forces themselves. Marks: 3 | Difficulty: Moderate | Bloom: Apply | Topic: Particles of Matter Q3. How does understanding particles help explain everyday phenomena? Model Answer: • Everything is made of tiny particles. • In solids particles cannot move much; in gases they move freely. • This explains pressure of air, boiling of water, and how substances dissolve (e.g., sugar in tea). • Classification into elements, compounds and mixtures follows from particle behaviour. Marks: 3 | Difficulty: Moderate | Bloom: Understand | Topic: Light Q4. Outline the path of light studies described in the chapter. Model Answer: • Light reflects off flat and curved mirrors. • Light bends (refracts) when passing through lenses. • This explains images in a shiny spoon and how corrective glasses help us see clearly. • Rough surfaces and the Moon also reflect light, leading to phases of the Moon. Marks: 3 | Difficulty: Moderate | Bloom: Understand | Topic: Ecosystems Q5. What is the significance of ecosystems in the Grade 8 journey? Model Answer: • Living organisms (from insects to whales, grass to trees) depend on and respond to air, water, sunlight and other organisms. • These relationships form ecosystems that support life. • Understanding ecosystems prepares us to recognise Earth’s delicate balance and the challenges it faces. Marks: 3 | Difficulty: Difficult | Bloom: Apply | Topic: Scientific Investigation Q6. Using the puri example, explain the idea of controllable variables and observations. Model Answer: • Controllable variables: thickness/size of dough, type of flour, oil temperature, way of dropping dough. • Observations/measurements: whether it puffs (yes/no), time to puff (seconds), whether thick dough still gives a thin side. • Changing only one variable at a time while keeping others constant allows clear conclusions. Marks: 3 | Difficulty: Difficult | Bloom: Evaluate | Topic: Nature of Science Q7. Why is systematic investigation important even for simple everyday phenomena? Model Answer: • It is the method used in all scientific experiments, simple or complex. • Asking focused questions, controlling variables, recording observations and generating further questions leads to reliable understanding. • Even the puffing of a puri is not fully understood, showing that careful investigation continues to be needed. Marks: 3 | Difficulty: Difficult | Bloom: Evaluate | Topic: Climate & Science Q8. How can science help address the climate challenges mentioned in the chapter? Model Answer: • Human activities influence Earth’s temperature and climate patterns.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 11 • The same principles – observing, measuring, experimenting – help us understand these changes. • Science can guide our actions to protect the delicate balance on which life depends. • Students are encouraged to try solving these problems with Curiosity as guide.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 12 SECTION E – LONG ANSWER QUESTIONS (6 Questions | 5 Marks) Answer in a structured manner (about 8 lines / points). Marks: 5 | Difficulty: Moderate | Bloom: Understand | Topic: Chapter Overview Q1. Describe the overall investigative journey planned for Grade 8 Science as outlined in Chapter 1. Model Answer: • Starts with tiny microbes in a drop of water – helpful and harmful; health, food, exercise, medicines, vaccines. • Electric current – heating and magnetic effects; then fundamental forces that change motion. • Pressure and its link to air movement, winds and cyclones. • Particles of matter, classification (elements, compounds, mixtures) and solutions. • Light – reflection, refraction, lenses, Moon phases and calendars. • Ecosystems and relationships between organisms and environment. • Finally, Earth as a habitable planet and climate challenges; science as a guide to protect life. Marks: 5 | Difficulty: Difficult | Bloom: Apply | Topic: Puri Investigation Q2. Explain the scientific approach to investigating why a puri puffs up, based on the chapter. Model Answer: • Start with a focused scientific question: What factors change the way a puri puffs? • Identify controllable variables: dough thickness/size, flour type, oil temperature, dropping method. • Decide what to observe/measure: does it puff? time taken? thickness of sides? • Change only one variable at a time, keep others constant. • Record all observations (sight, smell, sound, smoke, etc.). • After one round, generate further questions (fresh vs stored dough, pricking a hole, etc.). • This systematic method is how all scientific experiments are done. Marks: 5 | Difficulty: Difficult | Bloom: Evaluate | Topic: Philosophy of Investigation Q3. Discuss the importance of balancing ‘roots’ and ‘kite’ in scientific investigation. Model Answer: • Roots: Careful observation, connection to environment, traditions and cultural/natural heritage – the solid ground of knowledge. • Kite: Curiosity that takes flight, creative thinking, exploration of the unknown. • Investigation works best when both are balanced – grounded observation + freedom of creative ideas. • Without roots, ideas lack evidence; without the kite, learning remains limited to known facts. • Grade 8 aims to develop young scientists who observe carefully and think creatively. Marks: 5 | Difficulty: Difficult | Bloom: Analyse | Topic: Light & Moon Q4. How does the study of light in Grade 8 connect everyday objects to celestial phenomena? Model Answer: • Reflection from flat/curved mirrors and refraction through lenses explain images in spoons and corrective glasses. • Rough surfaces also reflect light – so does the Moon. • Relative positions of Earth, Moon and Sun illuminate different parts of the Moon → phases. • Observing these periodic phases, together with sunrises and sunsets, led to the first calendars. • Thus everyday optics is linked to motions of celestial objects that shape our time-keeping. Marks: 5 | Difficulty: Difficult | Bloom: Evaluate | Topic: Earth & Climate Q5. Explain why Earth is described as ‘just right’ for life and what threatens this balance. Model Answer: • Perfect distance from the Sun keeps water liquid. • Atmosphere supplies oxygen and shields from harmful UV rays. • Complex ecosystems of interdependent organisms thrive under these conditions. • Human activities can cause small temperature changes, disrupting climate patterns with dangerous consequences. • Humans are both the source of the problem and the possible solution; science must guide protective action. Marks: 5 | Difficulty: Difficult | Bloom: Create | Topic: Science in Everyday Life Q6. “Science is everywhere – you don’t need a fancy laboratory.” Justify this statement with examples from the chapter and suggest how a student can begin investigating at home. Model Answer: • The chapter uses the kitchen and the puffing of a puri/phulka/batura as a scientific puzzle. • Controllable variables and observable outcomes can be studied with everyday materials. • Simple questions (“What happens if…?”) start the process.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 13 • Student can begin by choosing one variable (e.g., oil temperature), keeping dough identical, recording puff time and appearance, and asking follow-up questions. • Careful notes and changing one factor at a time turn the kitchen into a laboratory of curiosity.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 14 SECTION F – COMPETENCY-BASED QUESTIONS (8 Questions) Real-life situations testing application, reasoning and decision-making. Marks: 3–4 | Difficulty: Difficult | Bloom: Create | Topic: Investigation Design Q1. Your younger sibling asks why one side of a puri is thinner. How would you turn this into a scientific investigation at home? List the steps. Model Answer: • Frame a question: What factors affect how a puri puffs and which side becomes thinner? • List variables to control (thickness, flour, oil temperature, dropping method). • Decide observations (puff yes/no, time, thickness of sides). • Change one variable at a time; record everything. • Compare results and ask further questions. Marks: 3–4 | Difficulty: Difficult | Bloom: Create | Topic: Controlled Experiment Q2. A student wants to test whether oil temperature affects puri puffing. Design a fair test. Model Answer: • Keep dough thickness, size, flour type and dropping method identical. • Prepare three oil temperatures (e.g., moderately hot, hot, very hot). • Fry identical dough circles one by one; record time to puff and final appearance. • Compare results to see the effect of temperature alone. Marks: 3–4 | Difficulty: Moderate | Bloom: Evaluate | Topic: Nature of Science Q3. During a class discussion a student says “Science is only about memorising facts.” How would you respond using ideas from Chapter 1? Model Answer: • Chapter emphasises learning how to find new facts, not only learning existing ones. • Investigation = focused questions + experiments + observations that improve understanding. • Even simple phenomena (puri puffing) are not fully understood – science is evolving. • Students become young investigators exploring real-world puzzles. Marks: 3–4 | Difficulty: Moderate | Bloom: Apply | Topic: Pressure & Weather Q4. You notice a gentle breeze on some days and strong winds on others. How does the chapter’s idea of pressure help explain this? Model Answer: • Air movement is driven by pressure differences. • Small difference → gentle breeze. • Larger difference → strong winds; still larger → possible cyclones. • Understanding force distributed over area (pressure) explains these weather events. Marks: 3–4 | Difficulty: Moderate | Bloom: Apply | Topic: Moon & Calendars Q5. A calendar on the classroom wall shows dates linked to lunar months. Connect this to the chapter’s discussion of the Moon. Model Answer: • Moon phases arise from relative positions of Earth, Moon and Sun. • Periodic observation of these phases (with sunrises/sunsets) allowed humans to create the first calendars. • Thus everyday time-keeping is linked to celestial motions studied through careful observation. Marks: 3–4 | Difficulty: Difficult | Bloom: Evaluate | Topic: Climate Q6. Your family is discussing climate change news. Using the chapter, explain why science is important in this context. Model Answer: • Human activities can change Earth’s temperature and disrupt climate patterns. • Observing, measuring and experimenting – the core of science – help us understand these changes. • Science can guide actions to protect the balance that makes Earth habitable. • We are both the problem and the possible solution. Marks: 3–4 | Difficulty: Difficult | Bloom: Create | Topic: Symbolism in Practice Q7. Suggest two ways a Class 8 student can practise ‘staying rooted’ and two ways to let the ‘kite soar’ while studying science. Model Answer:

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 15 • Rooted: Careful observation of everyday events; recording data accurately; linking learning to local environment and heritage. • Kite: Asking new “what if” questions; designing simple experiments; imagining solutions to larger problems such as climate challenges. Marks: 3–4 | Difficulty: Difficult | Bloom: Evaluate | Topic: Role of Young Scientists Q8. Why does the chapter say that challenges ahead won’t always be easy, yet still encourage students to try? Model Answer: • Climate and planetary challenges are complex and urgent. • The same scientific principles (observe, measure, experiment) are key to understanding and protecting life’s balance. • With Curiosity as guide, students can contribute to solutions – becoming investigators rather than only learners.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 16 SECTION G – ASSERTION & REASON (6 Questions) Directions: Assertion (A) is followed by Reason (R). Choose: (a) Both A and R true and R explains A (b) Both A and R true but R does not explain A (c) A true, R false (d) A false, R true Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Symbolism Q1. Assertion (A): The root symbol on left-hand pages represents the foundation of knowledge. Reason (R): It keeps us connected to our environment, traditions and cultural and natural heritage. Answer: (a) Explanation: Both true; R correctly explains the meaning of the root symbol. Marks: 1 | Difficulty: Moderate | Bloom: Apply | Topic: Controlled Experiments Q2. Assertion (A): Investigation in science requires changing many variables at the same time. Reason (R): Changing only one variable at a time helps us see the effect of that variable clearly. Answer: (d) Explanation: A is false; R is true – fair tests change one factor while keeping others constant. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Earth Q3. Assertion (A): Earth’s atmosphere protects us from harmful ultraviolet rays. Reason (R): The atmosphere also provides the oxygen we breathe. Answer: (b) Explanation: Both statements true, but R does not explain the UV-shielding role; both are separate benefits. Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Moon Phases Q4. Assertion (A): Phases of the Moon are caused by clouds covering different parts of the Moon. Reason (R): Relative positions of Earth, Moon and Sun determine which part of the Moon is illuminated. Answer: (d) Explanation: A is false; R is true and gives the correct explanation. Marks: 1 | Difficulty: Moderate | Bloom: Apply | Topic: Science Everywhere Q5. Assertion (A): Science is everywhere and does not always need a fancy laboratory. Reason (R): Even the kitchen can be a place for careful observation and simple experiments. Answer: (a) Explanation: Both true; the kitchen example supports the assertion. Marks: 1 | Difficulty: Difficult | Bloom: Evaluate | Topic: Climate Q6. Assertion (A): Human activities have no effect on Earth’s climate. Reason (R): Small changes in temperature caused by humans can disrupt climate patterns. Answer: (d) Explanation: A is false; R is true – the chapter stresses human influence and responsibility.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 17 SECTION H – CASE-BASED QUESTIONS (3 Cases) Read the passage carefully and answer the questions that follow. Case Study 1 – The Puri Puzzle A student noticed that a puri puffs up like a balloon in hot oil and one side becomes thinner. She decided to investigate. She listed possible factors: thickness of dough, type of flour, temperature of oil, and the way the dough is dropped. She decided to change only the oil temperature while keeping dough thickness and dropping method the same. She recorded whether the puri puffed, the time taken, and any smoke or smell. Marks: 1–2 | Difficulty: Moderate | Bloom: Apply | Topic: Investigation Q1.1. Which scientific practice is the student following by changing only oil temperature? Answer: Controlling variables / fair test – changing one factor at a time while keeping others constant. Marks: 1–2 | Difficulty: Moderate | Bloom: Apply | Topic: Investigation Q1.2. Name two observations she planned to record. Answer: Whether the puri puffed (yes/no); time taken to puff; presence of smoke or smell (any two). Marks: 1–2 | Difficulty: Difficult | Bloom: Create | Topic: Investigation Q1.3. Suggest one further question she could ask after the first round of experiments. Answer: Do puris puff better when made from fresh dough or stored dough? / What happens if a hole is pricked before frying? (any valid follow-up) Case Study 2 – Root and Kite On every left-hand page of the textbook a root is drawn; on every right-hand page a kite soars. The authors explain that investigation works best when we balance the solid ground of careful observation with the freedom of creative thinking. Marks: 1–2 | Difficulty: Moderate | Bloom: Understand | Topic: Symbolism Q2.1. What does the root symbolise? Answer: Deep, solid foundation of knowledge connected to environment, traditions and cultural/natural heritage. Marks: 1–2 | Difficulty: Moderate | Bloom: Understand | Topic: Symbolism Q2.2. What does the kite remind students to do? Answer: Allow curiosity to take flight and explore the unknown while staying grounded in observation. Marks: 1–2 | Difficulty: Difficult | Bloom: Evaluate | Topic: Symbolism Q2.3. Why is the balance between root and kite important for a young scientist? Answer: Without careful observation (root) ideas lack evidence; without creative curiosity (kite) learning stays limited. Both together produce reliable and imaginative science. Case Study 3 – Earth and Climate The final part of the chapter notes that Earth lies at the perfect distance from the Sun, has liquid water and a protective atmosphere. Yet human activities can cause small temperature changes that disrupt climate patterns. The text states that we are at the heart of both the problem and any possible solution. Marks: 1–2 | Difficulty: Moderate | Bloom: Understand | Topic: Earth & Climate Q3.1. Give two reasons why Earth is described as ‘just right’ for life. Answer: Perfect distance from Sun keeps water liquid; atmosphere provides oxygen and shields from harmful UV rays. Marks: 1–2 | Difficulty: Difficult | Bloom: Analyse | Topic: Earth & Climate Q3.2. What is meant by ‘we are at the heart of both the problem and the solution’? Answer: Humans influence climate through activities (problem) but can also use science to understand changes and guide protective actions (solution). Marks: 1–2 | Difficulty: Moderate | Bloom: Apply | Topic: Earth & Climate Q3.3. Which scientific practices does the chapter say will help protect Earth’s balance? Answer: Observing, measuring and experimenting – the same principles that guide the middle-school science journey.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 18 SECTION I – SOURCE-BASED QUESTIONS (3 Sets) Study the given information and answer the questions. Source Set 1 – Journey Overview “This year, our investigative adventure will take us on a journey from the tiny microbes we can’t see to planet-wide challenges we can’t ignore… We will start by examining something as small as a single drop of water… Then electric current… forces… pressure… particles… light… Moon phases… ecosystems… and finally what makes Earth ‘just right’ for life.” Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Overview Q1.1. What is the starting point of the Grade 8 science journey? Answer: Examining tiny microbes in a single drop of water (invisible living world). Marks: 1 | Difficulty: Moderate | Bloom: Remember | Topic: Overview Q1.2. Name three intermediate topics listed in the journey. Answer: Electric current / forces / pressure / particles of matter / light / Moon phases / ecosystems (any three). Marks: 1 | Difficulty: Moderate | Bloom: Understand | Topic: Overview Q1.3. What is the final focus of the journey? Answer: Understanding what makes Earth suitable for life and recognising the climate challenges it faces. Source Set 2 – Systematic Investigation “It is better to change only one thing at a time while keeping the other conditions same… It is also a good idea to keep notes of everything that you see and sense… After doing one round of experiments, you may think of more questions… This is exactly how all scientific experiments, from simple to the most complicated are done.” Marks: 1–2 | Difficulty: Moderate | Bloom: Understand | Topic: Scientific Method Q2.1. Why should only one variable be changed at a time? Answer: So that the effect of that single variable can be clearly observed and conclusions remain reliable. Marks: 1–2 | Difficulty: Moderate | Bloom: Apply | Topic: Scientific Method Q2.2. What should be recorded during an experiment? Answer: Everything seen and sensed – e.g., appearance, time, smell, smoke, sound, etc. Marks: 1–2 | Difficulty: Difficult | Bloom: Analyse | Topic: Scientific Method Q2.3. What happens after one round of experiments according to the text? Answer: New questions arise, leading to further investigation – the process is continuous. Source Set 3 – Science and Society “At the heart of both the problem—and any possible solution—is us. We are the ones influencing Earth’s climate. But we are also the ones who can—and must—use science to understand these changes and guide our actions… We hope some of you will try to solve these difficult problems with Curiosity as your guide.” Marks: 1–2 | Difficulty: Moderate | Bloom: Remember | Topic: Climate & Responsibility Q3.1. Who is described as being at the heart of both the climate problem and its solution? Answer: We / human beings. Marks: 1–2 | Difficulty: Moderate | Bloom: Understand | Topic: Climate & Responsibility Q3.2. What role must science play according to the passage? Answer: Help us understand climate changes and guide our actions to protect Earth’s balance. Marks: 1–2 | Difficulty: Difficult | Bloom: Evaluate | Topic: Climate & Responsibility Q3.3. What invitation does the chapter extend to students? Answer: To try to solve difficult planetary problems with Curiosity (the spirit of investigation) as their guide.

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 19 SECTION J – HOTS (6 Questions) These questions require critical thinking, analysis and evaluation. Marks: 4–5 | Difficulty: Difficult | Bloom: Evaluate | Topic: Nature of Science Q1. “Even the simple everyday observation of a puri puffing is not really completely understood by scientists today.” What does this statement tell us about the nature of science? Model Answer: • Science is an ongoing process; many everyday phenomena still hold unanswered questions. • Complete understanding is not always available; investigation continues. • Students are invited to participate in this open-ended enquiry rather than only memorise finished answers. • Humility and curiosity remain essential even for professional scientists. Marks: 4–5 | Difficulty: Difficult | Bloom: Analyse | Topic: Learning Progression Q2. Compare the approach of Grade 6, Grade 7 and Grade 8 to science learning as described in the chapter. How does each stage prepare students for the next? Model Answer: • Grade 6: Wonder and simple why/how questions – builds curiosity. • Grade 7: Science evolves; answers open new questions – builds flexibility of thought. • Grade 8: Focused questions + experimental design + explanation – builds investigative skill. • Each stage scaffolds the next, moving from wonder → evolving ideas → systematic investigation. Marks: 4–5 | Difficulty: Difficult | Bloom: Create | Topic: Experiential Learning Q3. Design a short classroom activity that helps students experience both the ‘root’ and the ‘kite’ aspects of investigation. Model Answer: • Root: Observe a local phenomenon carefully (e.g., how a leaf floats or how ice melts) and record detailed notes. • Kite: Brainstorm creative “what if” questions and design one simple test of a new idea. • Share findings and reflect on how observation and imagination worked together. • Emphasise that both careful data and creative questions are needed. Marks: 4–5 | Difficulty: Difficult | Bloom: Evaluate | Topic: Pedagogy of the Chapter Q4. Why might the authors have chosen the puffing of a puri as the central example of scientific investigation rather than a laboratory experiment? Model Answer: • It is familiar, accessible and requires no special equipment – science is everywhere. • It shows that complex science can start from everyday observation. • It models variable control and systematic recording in a context students can replicate at home. • It demonstrates that even “simple” phenomena can be scientifically deep and not fully solved. Marks: 4–5 | Difficulty: Difficult | Bloom: Analyse | Topic: Science & Society Q5. The chapter links calendars on Earth to motions of the Moon and Sun. What larger message about science does this connection convey? Model Answer: • Everyday human practices (time-keeping) are rooted in careful observation of nature. • Science connects local experience to celestial phenomena. • Observation + pattern recognition → practical tools (calendars). • Encourages students to look for similar hidden connections between daily life and larger natural systems. Marks: 4–5 | Difficulty: Difficult | Bloom: Create | Topic: Curiosity & Investigation Q6. If you were to write one new “Probe and ponder” question for the first page of this chapter, what would it be and why? Model Answer: • Example: “What everyday object in your home could become the starting point of a scientific investigation, and what one variable would you change first?” • Reason: It invites personal ownership of enquiry, applies the chapter’s method immediately, and balances root (observation of home) with kite (creative choice of variable).

Premium CBSE/KV Question Bank | Class 8 Science Ch-1 | Page 20 PREPARED BY Ekaparna Sahu B.Sc., M.Sc., B.Ed., M.Ed. Premium KV & CBSE Competency-Based Question Bank Class 8 Science | Chapter 1 Exploring the Investigative World of Science Academic Session 2026–27 Based exclusively on NCERT Textbook – Curiosity (Science) Grade 8 Aligned with CBSE Competency-Based Assessment Pattern & KVS Guidelines NEP 2020 | Bloom's Taxonomy | CBE Framework Practice • Learn • Revise • Excel © For educational use | Original questions based on NCERT content