Class 8 Science Curiosity Chapter 1 Solutions (NCERT 2026–27) – Exploring the Investigative World of Science

These Class 8 Science Curiosity Chapter 1 solutions cover Exploring the Investigative World of Science from the new NCF-2023 textbook (2026–27). Chapter 1 is the year’s opening chapter: it teaches you how to think and work like a scientist through careful observation, focused questions and simple experiments, rather than presenting a single science topic.

Class: 8 Subject: Science Book: Curiosity Chapter: 1 Type: Introductory (Probe and ponder + Activities) Session: 2026–27
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Note: Chapter 1 of Curiosity is an introductory chapter and does not have an end-of-chapter “Keep the curiosity alive” exercise. Its questions are the first-page “Probe and ponder” prompts and the in-text investigation activities, all reproduced and answered below.

Class 8 Science Curiosity Chapter 1 Solutions – Overview

Chapter 1 of Curiosity, Exploring the Investigative World of Science, sets the tone for Grade 8 science. It reminds us that in Grade 6 science began with wonder and simple “Why?” and “How?” questions, and in Grade 7 we saw that science keeps evolving. Now we enter the investigative world, where we learn not just new facts but how to find new facts. Using the everyday example of a puri puffing in hot oil, the chapter shows the idea of systematic investigation: asking a focused question, deciding what to change/control and what to observe/measure, changing only one thing at a time, and keeping careful notes. The root-and-kite page symbols capture its big idea — stay grounded in real observation while letting ideas soar.

Key Concepts & Definitions

Investigation: a systematic way of studying the world — far more than just looking at something. It means asking focused questions, designing simple experiments, and using observations to improve our understanding.

Scientific question: a clear, testable question such as “What different things change the way a puri puffs up when fried?” that can be answered by experiment.

Variables we control: the things we deliberately change in an experiment — e.g. the thickness or size of the rolled dough, the type of flour (atta, maida), the oil temperature, or the way the dough is dropped into the oil.

Things we observe / measure: what we record to see if a change mattered — either yes/no observations (did the puri puff up?) or a number (how many seconds to puff up).

Fair test (change one thing at a time): to find the effect of one factor, change only that factor while keeping all other conditions the same.

Keeping notes: recording everything you see and sense — did the oil splatter, smell or smoke? — because good records lead to new questions.

“Probe and Ponder” Questions — Answers

These first-page prompts are invitations to spark curiosity, not exam questions; the answers below are model explanations a young scientist could give.

1. Why is one side of a puri thinner than the other?

ANSWER When a puri is fried, the surface dough quickly forms a thin, sealed skin. The water inside turns to steam, which cannot escape and pushes the layers apart, so the puri puffs up like a balloon. The two surfaces do not heat or set in exactly the same way — the side that touches the hot oil first, the way the dough was rolled (often slightly thicker at the centre), and how it is flipped all make one wall set thinner than the other. Scientists say even this everyday observation is not yet fully understood, so it is a perfect puzzle to investigate. (Your own careful reasoning is accepted.)

2. Are there more grains of sand on all the beaches and deserts of the world, or more stars in our galaxy?

ANSWER This is best answered by estimation rather than counting. Scientists estimate that our galaxy, the Milky Way, contains roughly 100–400 billion stars. Estimates of the grains of sand on all of Earth’s beaches and deserts are even larger — somewhere around a few thousand billion billion grains. So, by current estimates, the grains of sand far outnumber the stars in our galaxy. The valuable skill here is making a sensible rough estimate from reasonable assumptions. (Numbers are approximate.)

3. Right from Grade 6, we’ve observed the incredible diversity of plants and animals around us. From the different shapes of leaves to the many kinds of insects—why has nature created such a vast variety?

ANSWER Such variety exists because living things must survive in many different surroundings. Each habitat — a pond, a desert, a forest, a cold mountain — suits different shapes, sizes and habits, so a huge range of forms can find food, escape danger and reproduce. Over very long periods, living things gradually change and adapt to their environments, and this slow process builds up the enormous diversity of leaves, insects and other organisms we see today. (Your own example is accepted.)

4. Is there such a question that makes you curious about the world? Write it here!

ANSWER This is your personal “wonder” question, so any genuine, curious question is correct. Good examples: Why does dough rise when we leave it to rest? Why does the bright part of the Moon shrink after purnima? Why does cut fruit turn brown? A strong question is one you could actually investigate — something you can observe, change and test. Write your own question and think of one simple experiment that might begin to answer it.

Investigating Like a Scientist — The Puri Example

The chapter uses the kitchen question “Why is one side of a puri thinner than the other?” to demonstrate systematic investigation. The activity-style questions woven into the text are answered below.

Q. What are the different things that may change the way a puri puffs up when fried?

ANSWER Several factors can be changed or controlled: the thickness of the rolled dough, the size of the dough circle, the type of flour used (atta, maida, etc.), the temperature of the hot oil, and the way the dough is dropped into the oil (dropped vertically, slid in at an angle, or slid in slowly).

Q. What can we observe or measure to see if these changes made any difference?

ANSWER Some observations are simple yes/no answers — for example, did the puri puff up, and did a very thick layer of dough still give a thin side? Others are numbers we can measure, such as the time in seconds the puri takes to puff up. We should also note sensory clues — whether the oil splattered, smelled or smoked.

Q. Why should we change only one thing at a time while keeping the other conditions the same?

ANSWER Changing only one factor at a time makes it a fair test. For example, to study the effect of boiling-hot, hot and not-very-hot oil, we should use dough circles of the same thickness and drop them in the same way. Then any difference in puffing can be linked to the oil temperature alone, and not to some other change.

Q. After one round of experiments, what further questions might a young scientist ask?

ANSWER Good investigations open up new questions, such as: Do puris puff better when made from fresh dough or stored dough? What happens if I prick a hole in the puri before frying? This is exactly how all scientific experiments — from the simplest to the most complicated — are carried out, which is the idea of systematic investigation.

Common Misconceptions to Avoid

Watch out for these

  • Thinking science only happens in a fancy laboratory — even your kitchen is a great place to observe, ask questions and experiment.
  • Believing investigation means “just looking” — real investigation also means asking focused questions and testing them.
  • Changing many things at once in an experiment — then you cannot tell which change caused the result.
  • Thinking observations must always be numbers — useful data can also be simple yes/no observations or sensory notes.
  • Assuming everyday things are fully explained — even the puffing of a puri is not yet completely understood by scientists.
  • Forgetting to keep notes — records of what you see and sense are what let you compare results and ask new questions.

Extra Practice Questions

Very Short Answer Type Questions

Q1. What does “investigation” mean in science?

ANSWERA systematic way of studying something — asking focused questions, doing simple experiments and using observations to improve understanding.

Q2. Give one example of a factor you could change while investigating why a puri puffs up.

ANSWERThe thickness of the rolled dough (or the oil temperature, or the type of flour).

Q3. Name one quantity you could measure in this experiment.

ANSWERThe time (in seconds) the puri takes to puff up.

Short Answer Type Questions

Q1. Why is it important to change only one variable at a time in an experiment?

ANSWERIf only one factor is changed while the rest are kept the same, it becomes a fair test. Any change in the result can then be linked to that one factor alone, instead of being confused by several changes at once.

Q2. The chapter uses a root and a kite as page symbols. What do they stand for?

ANSWERThe root stands for a deep, solid foundation of knowledge that keeps us connected to our environment and heritage, while the kite reminds us that curiosity must take flight to explore the unknown. Together they mean we should stay grounded in real observation yet let our ideas soar.

Long Answer Type Question

Q1. Describe how you would investigate the question “Does oil temperature affect how quickly a puri puffs up?” like a scientist.

ANSWERFirst I would frame the scientific question clearly. Then I would decide the factor to change — the oil temperature (boiling-hot, hot, not very hot) — and the factors to keep the same: the same flour, the same dough thickness, the same size of circle, and dropping each puri in the same way. I would measure the time in seconds each puri takes to puff up and note whether it puffed at all, along with any splattering or smoke. By changing only the temperature and keeping everything else constant, the test is fair, so any difference in puffing time can be linked to the oil temperature. I would record all results carefully, repeat the trials, and then use the findings to ask further questions — this is systematic investigation.

MCQs & Assertion–Reason

1. In Grade 8 science, we mainly learn to:

(a) memorise more facts    (b) find out how to discover new facts    (c) avoid asking questions    (d) copy answers

2. “Investigation” in science means:

(a) only looking at something    (b) guessing the answer    (c) asking focused questions and testing them    (d) reading without observing

3. While studying why a puri puffs up, which of these is a factor you can control?

(a) the time it takes to puff    (b) the thickness of the dough    (c) whether it smells    (d) whether it puffed (yes/no)

4. Which of these is something you would observe or measure?

(a) the type of flour    (b) the oil temperature you set    (c) the time in seconds to puff up    (d) the size of the dough circle

5. To make a fair test, in one experiment you should change:

(a) many things together    (b) only one thing at a time    (c) nothing at all    (d) the observer

6. According to the chapter, doing simple experiments needs:

(a) a fancy laboratory    (b) expensive instruments    (c) only curiosity and careful observation    (d) a computer

7. The puffing of a puri is said to be:

(a) fully understood by scientists    (b) not completely understood even today    (c) impossible to study    (d) unimportant

8. The root symbol on the pages of the book stands for:

(a) curiosity taking flight    (b) a solid foundation of knowledge    (c) speed    (d) measurement

9. The kite symbol on the pages reminds us that:

(a) we should never change ideas    (b) curiosity must take flight to explore the unknown    (c) science is boring    (d) only facts matter

10. While experimenting, keeping notes of splatter, smell and smoke is useful because:

(a) it wastes time    (b) it has no value    (c) good records help compare results and raise new questions    (d) it replaces the experiment

Answer key: 1-(b), 2-(c), 3-(b), 4-(c), 5-(b), 6-(c), 7-(b), 8-(b), 9-(b), 10-(c).

For each Assertion–Reason question, choose: (A) Both true and the Reason correctly explains the Assertion; (B) Both true but the Reason is not the correct explanation; (C) Assertion true, Reason false; (D) Assertion false, Reason true.

A-R 1. Assertion: Science can be done even in an ordinary kitchen.

Reason: Simple experiments need only curiosity and careful observation, not a fancy laboratory.

A-R 2. Assertion: In a good experiment we change only one factor at a time.

Reason: Keeping other conditions the same makes the test fair so the result can be linked to that one factor.

A-R 3. Assertion: Investigation in science means simply looking at things.

Reason: Investigation also means asking focused questions, experimenting and explaining what we observe.

A-R 4. Assertion: The puffing of a puri is completely understood by scientists.

Reason: Even simple everyday observations can still be open scientific puzzles.

A-R 5. Assertion: Keeping careful notes during an experiment is a good practice.

Reason: Records of what we see and sense help us compare results and think of new questions.

Answer key: 1-(A), 2-(A), 3-(D), 4-(C), 5-(A).

Quick Revision Summary

  • Grade 8 science is about learning how to find new facts, not just learning more facts.
  • Investigation = asking focused questions, doing simple experiments and using observations to improve understanding.
  • Plan an experiment by deciding what to change/control and what to observe/measure (yes/no or a number).
  • Make a fair test by changing only one thing at a time and keeping the rest the same.
  • Keep notes of everything you see and sense; good records lead to new questions.
  • The root (solid foundation) and the kite (soaring curiosity) symbolise the spirit of the book; even a puffing puri is still not fully understood.

Real-life Applications

The investigative habit works far beyond the kitchen. A cook tests “change one thing at a time” when adjusting oil temperature or dough; a gardener does the same when checking why one plant grows better than another; and a student improving a science-fair project changes a single variable per trial. The same steps — ask a question, control variables, observe and measure, keep notes — are exactly how doctors test medicines, how engineers improve machines, and how researchers study big questions like whether the world is getting warmer. Learning this method in Chapter 1 prepares you to investigate every later topic in Curiosity.

How to score full marks in this chapter

Clearly separate the things you control (e.g. dough thickness, oil temperature, flour type) from the things you observe or measure (puffed yes/no, time in seconds). For any “design an experiment” answer, always state your scientific question, name the one variable you change, list what you keep the same to make it a fair test, and mention keeping notes. Use the textbook’s own examples — the puri, the root and the kite — to show you have read the chapter.

Frequently Asked Questions

What is Class 8 Science Curiosity Chapter 1 about?

Chapter 1, Exploring the Investigative World of Science, teaches how to think and work like a scientist — asking focused questions, designing simple experiments, deciding what to change and what to observe, making fair tests and keeping notes — using the everyday example of why a puri puffs up in hot oil.

Does Chapter 1 of Curiosity have an exercise?

No. It is an introductory chapter, so instead of an end-of-chapter exercise it has the first-page “Probe and ponder” questions and in-text investigation activities, all answered on this page.

Why is one side of a puri thinner than the other?

The surface dough quickly forms a sealed skin and trapped steam puffs the puri up; the two sides do not set in exactly the same way, so one wall ends up thinner. Scientists say this everyday observation is not yet fully understood — making it a good question to investigate.

Are these Class 8 Science Curiosity Chapter 1 solutions free?

Yes. All solutions are free and follow the official NCERT Curiosity textbook for 2026–27.

All Curiosity Chapters Class 8 Science Chapter 2 →
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