NCERT Class 8 Science Book Curiosity: What Each Chapter Teaches

The NCERT Class 8 Science book Curiosity is the official Class 8 Science textbook, with 13 chapters across 228 printed pages — and every chapter’s PDF is on this page, hosted on NCERT’s own site.

This page also shows what is inside each chapter before you open it: how many named sections, hands-on activities and numbered figures every chapter carries, with the page each section starts on. If someone asks you which chapter has the cell, or where solutions begin, the chapter-by-chapter breakdown below answers it.

Chapter-wise PDFs of the official textbook

Every file below is NCERT’s own edition, hosted on ncert.nic.in under the hecu10 series — the same chapter files the official site serves. You can open Chapter 1 at https://ncert.nic.in/textbook/pdf/hecu101.pdf to check the source before downloading the rest.

The science NCERT Class 8 PDF, at a glance

These are the exact totals, counted from the textbook itself:

• 13 chapters
• 13 verified chapter PDFs, all on this page
• 228 printed pages in the official edition
• 107 named sections — NCERT’s numbered headings
• 24 activities — hands-on tasks the book sets
• 179 verified numbered figures indexed from the textbook

The chapters are not all one shape. The grouping below maps the book’s arc by theme — treat it as a reading map for navigation, not a structure NCERT prints inside the book:

Three chapters run 20 pages each — Chapters 2, 11 and 12 — the longest in the book. Chapter 1 is the shortest at 7 pages, so it reads quickly.

What is inside each chapter of Curiosity

The directory above counts NCERT’s own numbered headings. A “section” is one of the book’s numbered headings (2.1, 4.3, …), a “figure” is a numbered figure indexed from the textbook, an “activity” is a hands-on task the book sets, and a “question” would be an end-of-chapter exercise. Every count the chapter notes below use is checkable in that directory.

Chapter 1: Exploring the Investigative World of Science (pp. 1-7)

This opening chapter is an orientation to doing science itself — what it means to probe and ponder a question and to carry out an investigation, before the subject chapters begin.

1. Probe and ponder — the chapter’s opening frame for asking questions
2. Happy investigating! — its closing send-off into the chapters that follow

The book prints these two frames without numbered sections, so it is the only chapter in the book with no numbered sections, no activities and no indexed figures — a deliberate short warm-up.

Chapter 2: The Invisible Living World: Beyond Our Naked Eye (pp. 8-27)

The book’s first biology chapter introduces the cell as the basic unit of life and the microorganisms too small to see with the naked eye — from microscope views of onion peel and human cheek cells to the microbes in soil, food and water.

1. What Is a Cell? (p. 10)
2. What Are the Levels of Organisation in the Body of a Living Organism? (p. 14)
3. What Are Microorganisms? (p. 15)
4. How Are We Connected to Microbes? (p. 18)
5. Why Is Cell Considered to Be a Basic Unit of Life? (p. 23)

The chapter also moves through four sub-sections:

• Variation in shape and structure of cells (p. 13)
• Key players in cleaning the environment (p. 18)
• Microorganisms and food (p. 20)
• Amazing microalgae: tiny helpers in water (p. 22)

Its 15 indexed figures and single activity make it one of the book’s most visual life chapters — the cell sits at p. 10 and microorganisms at p. 15, anchoring the two halves.

Chapter 3: Bulletin Board (pp. 28-45)

This is the health chapter — what health means beyond simply not falling sick, how communicable and non-communicable diseases are caused and spread, and how prevention and treatment work.

1. Health: Is It More Than Not Falling Sick? (p. 29)
2. How Can We Stay Healthy? (p. 29)
3. How Do We Know That We Are Unwell? (p. 31)
4. Diseases: What Are the Causes and Types? (p. 32)
5. How to Prevent and Control Diseases? (p. 37)

It also works through these sub-sections:

• Maintain a healthy lifestyle (p. 30)
• Keep the environment clean (p. 31)
• Treatment of diseases (p. 39)

With 10 named sections but no activities and only 5 indexed figures, it is a reading-driven chapter rather than a diagram-driven one.

Chapter 4: Electricity: Magnetic and Heating Effects (pp. 46-61)

It shows what an electric current does beyond the wire — the magnetic effect that builds an electromagnet, the heating effect behind common household appliances, and the cells and batteries that generate the current.

1. Does an Electric Current Have a Magnetic Effect? (p. 47)
2. Does a Current Carrying Wire Get Hot? (p. 52)
3. How Does a Battery Generate Electricity? (p. 55)

Its sub-sections are:

• Electromagnets (p. 49)
• Lifting electromagnets (p. 52)
• Voltaic cell (p. 55)
• Dry cells (p. 57)
• Rechargeable batteries (p. 57)

Its 8 named sections, 3 activities and 10 indexed figures make it a practical chapter — the kind that pairs a compass with a wire.

Chapter 5: Exploring Forces (pp. 62-79)

Pushes and pulls — what a force can do to an object, how contact and non-contact forces differ, how friction opposes motion, and how force is measured as weight, ending with floating and sinking.

1. What Is a Force? (p. 63)
2. What Can a Force Do to the Objects on Which It Is Applied? (p. 64)
3. Are Forces an Interaction Between Two or More Objects? (p. 65)
4. What Are the Different Types of Forces? (p. 66)
5. Weight and Its Measurement (p. 72)
6. Floating and Sinking (p. 76)

Inside the types-of-forces question, it distinguishes:

• Contact forces (p. 66)
• Non-contact forces (p. 69)

It carries 5 activities, the second-most in the book, and 15 indexed figures that mostly show everyday pushes, pulls and falls.

Chapter 6: Pressure, Winds, Storms, and Cyclones (pp. 80-97)

Pressure explains the weather — how liquids push on container walls, how atmospheric pressure and wind form, and how storms, lightning and cyclones grow out of moving air.

1. Pressure (p. 81)
2. Pressure Exerted by Air (p. 85)
3. Formation of Wind (p. 87)
4. High-Speed Winds Result in Lowering of Air Pressure (p. 89)
5. Storms, Thunderstorms, and Lightning (p. 90)
6. Cyclone (p. 92)

The single activity sits inside a chapter of 17 indexed figures — the book’s fourth-highest — which trace water pressure, wind and cyclone formation.

Chapter 7: Particulate Nature of Matter (pp. 98-115)

Matter as particles — what matter is made of, what decides the states of matter, how interparticle spacing differs between solid, liquid and gas, and how particles spread by diffusion.

1. What Is Matter Composed of? (p. 99)
2. What Decides Different States of Matter? (p. 101)
3. How Does the Interparticle Spacing Differ in the Three States of Matter? (p. 107)
4. How Particles Move in Different States of Matter? (p. 109)

Each state gets its own sub-section:

• Solid state (p. 102)
• Liquid state (p. 104)
• Gaseous state (p. 105)

Its 14 indexed figures and 2 activities lean on schematic particle pictures rather than measurement.

Chapter 8: Nature of Matter (pp. 116-133)

Sorting everything around you into mixtures, elements and compounds — what counts as a pure substance, and what minerals have to do with it in daily life.

1. What Are Mixtures? (p. 117)
2. What Are Pure Substances? (p. 120)
3. What Are the Types of Pure Substances? (p. 121)
4. How Do We Use Elements, Compounds, and Mixtures? (p. 128)
5. What Are Minerals? (p. 129)

Sub-sections within these topics:

• Is air a mixture? (p. 118)
• Types of mixtures (p. 120)
• Elements (p. 123)
• Compounds (p. 124)

At 21 indexed figures it is the book’s second-most visual chapter, led by the iron-sulfur mixture experiment.

Chapter 9: The Amazing World of Solutes, Solvents, and Solutions (pp. 134-151)

Everyday mixtures — sugar in water, gulab jamuns in syrup — introduce solute, solvent and solution, move through saturated and unsaturated solutions, and end with density deciding what floats or sinks.

1. What Are Solute, Solvent, and Solution? (p. 135)
2. How Much Solute Can a Fixed Amount of Solvent Dissolve? (p. 136)
3. Solubility of Gases (p. 139)
4. Why Do Objects Float or Sink in Water? (p. 140)
5. What Is Density? (p. 140)

The chapter’s sub-sections cover:

• How does temperature affect the solubility of a solute? (p. 137)
• Determination of density (p. 141)
• Effect of temperature on density (p. 147)
• Effect of pressure on density (p. 148)

Its 24 indexed figures are the most of any chapter in the book — the measuring-cylinder set at pp. 144-146 walks through the density determination step by step.

Chapter 10: Light: Mirrors and Lenses (pp. 152-169)

The most hands-on chapter in the book — seven activities lead from concave and convex mirrors to the laws of reflection, the angle of incidence, and lenses.

1. What Are Spherical Mirrors? (p. 153)
2. What Are the Characteristics of Images Formed by Spherical Mirrors? (p. 155)
3. What Are the Laws of Reflection? (p. 157)
4. What Is a Lens? (p. 162)

It offers 7 activities, the most of any chapter — the book’s hands-on peak — alongside 16 indexed figures of ray behaviour.

Chapter 11: Keeping Time (pp. 170-189)

Linking the sky to the calendar — why the Moon’s phases wax and wane, how cultures built calendars including the Indian National Calendar, and why we launch artificial satellites.

1. How Does the Moon’s Appearance Change and Why? (p. 171)
2. How Did Calendars Come into Existence? (p. 178)
3. Are Festivals Related to Astronomical Phenomena? (p. 183)
4. Why Do We Launch Artificial Satellites in Space? (p. 185)

The calendar part splits into:

• Phases of the Moon (p. 172)
• Locating the Moon (p. 173)
• Making sense of our observations (p. 174)
• Lunar calendars (p. 179)
• Solar calendars (p. 180)
• Luni-solar calendars (p. 181)
• The Indian National Calendar (p. 182)

It runs 11 named sections but only 8 indexed figures, one of the book’s more text-driven chapters, where the Moon-orbit diagram at p. 176 does most of the visual work.

Chapter 12: How Nature Works in Harmony (pp. 190-209)

The ecology chapter — how organisms in a habitat form a community, who eats whom along a food chain and food web, and how an ecosystem keeps its balance.

1. How Do We Experience and Interpret Our Surroundings? (p. 191)
2. Who All Live Together in Nature? (p. 193)
3. Does Every Organism in a Community Matter? (p. 194)
4. What Are the Different Types of Interactions Among Organisms and their Surroundings? (p. 195)
5. Who Eats Whom? (p. 198)
6. What Happens to Waste in Nature? (p. 200)
7. How Does One Change Lead to Another? (p. 201)
8. How Do Interactions Maintain Balance in Ecosystems? (p. 202)
9. What Are the Benefits of an Ecosystem? (p. 203)

Two closing sub-sections look at:

• Human-made ecosystems (p. 205)
• How do healthy ecosystems serve our farms? (p. 205)

Its 20 indexed figures, the book’s third-highest, trace food chains, food webs and organism interactions.

Chapter 13: Our Home (pp. 210-228)

Earth as a planet — why it is unique, what makes it habitable through the greenhouse effect and its place in the habitable zone, how life continues through reproduction, and what threats put that balance at risk.

1. Why Is Earth a Unique Planet? (p. 211)
2. What Do the Planets of Our Solar System Look Like? (p. 212)
3. What Makes the Earth Suitable for Life to Exist? (p. 214)
4. What Allows Life to Be Sustained on Earth? (p. 217)
5. What Keeps Life from Disappearing? (p. 219)
6. What Are the Threats to Life on Earth? (p. 223)

Its questions unpack into:

• Position of the Earth (p. 214)
• Size of the Earth (p. 215)
• Magnetic field of the Earth (p. 217)
• Air, water, and sunlight (p. 217)
• Soil, rocks, and minerals (p. 218)
• Plants, animals, and microorganisms (p. 219)
• The importance of balance (p. 219)
• Asexual reproduction (p. 220)
• Sexual reproduction (p. 221)

With 15 named sections — the most of any chapter in the book — and 14 indexed figures that include the greenhouse effect and Mangalyaan, it is the book’s broadest sweep.

Study pages for each chapter

The listing below shows the current state of each chapter’s study page as it stands.

How to use the NCERT Class 8 Science book PDF

The chapters are not all the same shape, so a fixed front-to-back read is not the fastest route. This order works for this specific book:

1. Chapter 1 (pp. 1-7) — read this first. It is a short orientation to how science works and takes one sitting.
2. Chapters 2 and 3 (pp. 8-45) — the two life chapters build on each other: cells and microbes first, health and disease after.
3. Chapters 7, 8 and 9 (pp. 98-151) — the matter sequence is one connected run: particles, then mixtures and pure substances, then solutions and density. Treat it as a single unit.
4. Chapters 4, 5 and 6 (pp. 46-97) — electricity, forces and pressure are independent of the matter run, so they can be taken in any order.
5. Chapter 10 (pp. 152-169) — the most activity-heavy chapter in the book; leave time for the seven hands-on tasks.
6. Chapters 11, 12 and 13 (pp. 170-228) — the book closes with the sky, ecosystems and Earth in space.

Two practical notes:

• Watch the activity load. Chapter 10 packs 7 activities and Chapter 5 has 5, so both read slower than their page counts suggest.
• Book and syllabus are different documents. Textbook contents and the examinable syllabus are not always identical — check the current official syllabus before planning revision.

Related resources

This listing is maintained for the 2026-27 academic session using the NCERT textbook information available to us. NCERT remains the authority for confirming the latest edition.

• All NCERT books, by class — the full index of textbooks covered on this site.
• Class 8 hub — the landing page for every Class 8 book on this site.

Sources and data verification

• Edition described: the figures and counts on this page describe the NCERT Class 8 Science textbook Curiosity, official edition as published on ncert.nic.in.
• Scope: this page covers the 13 chapters of Curiosity only — not other Class 8 subjects and not other-language editions.
• Session: the listing is maintained for the current academic session using NCERT’s published information.
• Authority: NCERT settles textbooks, editions and PDFs; CBSE settles curriculum, syllabus and examinations. Textbook contents and the examinable syllabus are not always identical — check the current official syllabus.

Reference: NCERT Class 8 Science textbook, official edition on ncert.nic.in. Figure captions and section titles quoted from the textbook; page references are to the official PDF.

Frequently asked questions about this book

How many chapters are in the NCERT Class 8 Science book Curiosity?

Curiosity has 13 chapters across 228 printed pages, from Exploring the Investigative World of Science (pp. 1-7) to Our Home (pp. 210-228). The full chapter list, with page ranges and official PDF links, is in the download table at the top of this page.

Is the NCERT Class 8 Science Curiosity PDF official and free?

Yes. Every link on this page is NCERT’s own chapter file, hosted on ncert.nic.in, and the files are free to download. You do not need any other source.

Class 8 Science Chapter 1 — what is it called and what does it cover?

Chapter 1 is Exploring the Investigative World of Science (pp. 1-7). It is a brief orientation to doing science — what it means to probe, ponder and investigate — with no heavy content load.

Which chapter in Curiosity covers cells and microorganisms?

Chapter 2, The Invisible Living World: Beyond Our Naked Eye (pp. 8-27). The cell is introduced at page 10 and microorganisms at page 15.

Which chapters in the Class 8 Science book cover matter, mixtures and solutions?

Chapters 7, 8 and 9 (pp. 98-151) are the matter run: the particulate nature of matter, then mixtures, elements and compounds, then solutes, solvents and solutions.