Science · Class 6

A child in Class 6, 7 or 8 can read this book alone, understand every topic in the year's syllabus, and answer the school's own tests on it — no tutor, no parent sitting beside them.

That means the explaining is done here, on the page. It follows the NCERT textbook the school uses, chapter by chapter. Each chapter starts at the beginning, explains the idea in plain words, works an example before it asks a question. Every question is worked out at the back, so a wrong answer can be checked the same evening.

Science, Class 6, on the 2026–27 NCERT course.

1. The Wonderful World of Science

   • Science as a way of thinking, observing, and investigating — not merely a collection of facts
   • The scientific method: observe → question → guess (hypothesis) → test → analyse
   • Anyone who follows the scientific method is "working like a scientist" — everyday examples (pen that stops writing, bicycle tyre leak, faulty bulb)
   • Science is collaborative; scientists work in teams across the world
   • Chapter is an orientation — no testable concepts; sets curiosity as the book's central value
2. Diversity in the Living World

   • Biodiversity: variety of plants and animals in a region; each member has a role (interdependence)
   • Plant classification by stem: herbs (short, soft green stem), shrubs (many woody stems branching near ground), trees (tall, thick woody stem, branches higher up); also climbers and creepers
   • Leaf venation: reticulate (net-like, e.g. hibiscus) vs parallel (e.g. banana, grasses)
   • Root types: taproot (one main root + side roots, e.g. mustard, hibiscus) vs fibrous root (bunch of similar thin roots, e.g. grasses, wheat)
   • Correlation: plants with reticulate venation have taproots (dicots); plants with parallel venation have fibrous roots (monocots)
   • Seeds: dicotyledons (two cotyledons, e.g. chickpea, kidney beans) vs monocotyledons (one cotyledon, e.g. maize, wheat)
   • Animal grouping based on movement (fly, walk, swim, crawl, hop), body parts used, food, habitat
   • Habitat: place where plants/animals live; provides food, water, air, shelter
   • Terrestrial habitats: forests, deserts, grasslands, mountains; aquatic habitats: ponds, rivers, oceans
   • Amphibians: animals that live on both land and water (e.g. frogs)
   • Adaptations: special features enabling survival in a particular habitat (e.g. cactus fleshy stems for water storage; conical shape of deodar for snow-shedding; camel's wide hooves, hump, low water loss)
   • Biodiversity varies across regions because of distinct environmental conditions
   • Habitat loss leads to loss of biodiversity; conservation examples: Project Tiger (1973), Cheetah Reintroduction Project (2022)
   • Sacred groves as traditional community-protected biodiversity reserves
3. Mindful Eating

   • Food diversity in India: traditional foods vary by region, linked to locally grown crops and climate
   • Major nutrients: carbohydrates (energy-giving; e.g. rice, wheat, potato, sugar), fats (stored energy; e.g. ghee, oils, nuts), proteins (body-building; e.g. pulses, milk, egg, fish, meat)
   • Protective nutrients: vitamins (A, B1, C, D) and minerals (calcium, iodine, iron) — protect body from disease; required in small amounts
   • Deficiency diseases: scurvy (Vitamin C), rickets (Vitamin D), night-blindness/loss of vision (Vitamin A), beriberi (Vitamin B1), goitre (iodine), anaemia (iron), bone/tooth decay (calcium)
   • Roughage (dietary fibre): does not provide nutrients but aids smooth passage of stools; from fruits, vegetables, pulses, whole grains
   • Water: essential component; helps absorb nutrients, removes waste
   • Balanced diet: all essential nutrients + roughage + water in right amounts
   • Nutrient tests: iodine solution → blue-black colour = starch present; oily patch on paper = fat present; copper sulfate + caustic soda → violet colour = protein present
   • Junk foods: high sugar/fat, low protein/minerals/vitamins/fibre; lead to obesity and health problems
   • Millets (nutri-cereals): jowar, bajra, ragi, sanwa — nutrient-rich, iron and calcium sources, cultivable in varied climates
   • Food miles: distance food travels from producer to consumer; reducing food miles cuts cost, pollution, and supports local farmers
   • Food Safety and Standards Authority of India (FSSAI) regulates food quality; fortified foods (e.g. iodised salt)
4. Exploring Magnets

   • Magnetic materials: attracted to a magnet (iron, nickel, cobalt and their combinations)
   • Non-magnetic materials: not attracted to magnets (plastic, wood, glass, rubber, aluminium)
   • Poles of a magnet: North pole and South pole; poles always occur in pairs — no single pole possible (even broken magnets have both poles)
   • Iron filings stick most at poles (maximum attraction at poles, minimal at middle)
   • Freely suspended magnet rests along north–south direction because Earth behaves like a giant magnet
   • Magnetic compass: needle (a magnet) that indicates north–south direction; used for finding directions
   • Like poles (N–N or S–S) repel each other; unlike poles (N–S) attract each other
   • Property of repulsion is used to identify whether an object is a magnet (iron bar is attracted by both poles; another magnet repels one pole)
   • Magnetic effect acts through non-magnetic materials (wood, cardboard, plastic, glass)
   • Magnets can be made from iron by stroking with another magnet (magnetisation by stroking)
   • Magnets should be stored carefully: not heated, hammered, or dropped; stored in pairs with unlike poles adjacent
5. Length and Motion

   • Need for standard units: body-part measurements (handspan, arm, foot) vary person to person
   • International System of Units (SI): adopted globally; SI unit of length = metre (m)
   • Conversions: 1 km = 1000 m; 1 m = 100 cm; 1 cm = 10 mm
   • Measuring curved lengths: use a thread along the curve, then measure thread length with a straight scale
   • Reference point: fixed object/point from which position is described; motion requires a reference point
   • Motion: an object is in motion if its position changes with respect to a reference point over time
   • Types of motion: linear (along a straight line), circular (along a circular path), oscillatory (to and fro about a fixed position)
   • Examples: car on a straight road (linear); hands of a clock (circular); swing, pendulum (oscillatory)
6. Materials Around Us

   • Material: any substance used to create an object; objects can be made of single or multiple materials
   • Classification of materials by appearance: lustrous (shiny, e.g. metals — gold, silver, copper, iron) vs non-lustrous
   • Classification by hardness: hard (e.g. iron, stone) vs soft (e.g. cotton, sponge)
   • Classification by transparency: transparent (light passes fully, objects clearly visible — glass, clear water), translucent (light passes partially — oiled paper, frosted glass), opaque (light does not pass — wood, metal, stone)
   • Solubility in water: soluble (salt, sugar dissolve completely) vs insoluble (sand, chalk, sawdust do not dissolve)
   • Matter: anything that occupies space and has mass; mass = amount of matter; volume = space occupied
   • Different materials can make objects with the same function (e.g. chairs of wood, metal, plastic)
   • Materials selected for objects based on their properties (e.g. glass for windows → transparent; rubber for eraser → soft and flexible)
7. Temperature

   • Sense of touch is unreliable for judging temperature accurately (cold/hot perception is relative)
   • Temperature: reliable measure of hotness or coldness of a body; hotter body has higher temperature
   • Thermometer: device that measures temperature
   • Clinical thermometer: measures body temperature; digital clinical thermometers used in activity; normal human body temperature = 37.0 °C (average); range 35–42 °C
   • Laboratory thermometer: used for other measurements; cannot be used as clinical thermometer (different range and design)
   • Temperature scales: Celsius (°C), Fahrenheit (°F, 37 °C = 98.6 °F), Kelvin (K, SI unit; K = °C + 273.15)
   • Reading a thermometer correctly: eye-level, do not touch bulb with fingers, wash tip before and after use
   • Temperature varies across the day and with age, activity, and health
8. States of Water

   • Ice, water, and water vapour are three states (solid, liquid, gas) of the same substance
   • Evaporation: conversion of liquid water into water vapour; occurs at the surface; rate increases with temperature, wind, and surface area; responsible for drying of wet surfaces
   • Condensation: conversion of water vapour into liquid water (e.g. water droplets on outside of cold glass, dew on plants, water drops on lid of boiling utensil)
   • Humidity: amount of water vapour in the air
   • Melting: solid (ice) → liquid (water) on heating; freezing: liquid → solid on cooling
   • Three states of matter: solid (fixed shape and volume), liquid (fixed volume, takes shape of container), gas (neither fixed shape nor volume)
   • Water cycle: evaporation (water → vapour) → condensation (vapour → water droplets forming clouds) → precipitation (rain, hail, snow) → return to water bodies and groundwater; Sun drives the cycle
   • Cloud formation involves condensation of water vapour around tiny dust particles
   • Freshwater is a limited resource; most water is in oceans (not directly usable); importance of water conservation, reducing wastage, and preventing pollution
9. Methods of Separation

   • Mixtures: two or more substances mixed together (e.g. grains with stones and husk)
   • Handpicking: picking by hand based on differences in size, colour, shape; useful when impurity is in small quantity (e.g. stones from grains, black pepper from pulao)
   • Threshing: beating harvested stalks to separate grains from stalks
   • Winnowing: blowing air over a mixture; lighter component (husk, chaff) blown away; heavier component (grain) falls down; used for grain–husk separation
   • Sieving: passing mixture through a sieve; larger particles retained, smaller particles pass through; used for separating different sizes of solid particles (e.g. atta from bran, coarse sand from fine sand)
   • Sedimentation: heavier insoluble particles settle to the bottom of a liquid over time
   • Decantation: gently pouring the liquid from a container after sedimentation, leaving the settled solid behind; also used to separate oil and water (oil floats)
   • Filtration: passing mixture through a filter (e.g. filter paper); insoluble particles trapped as residue; used when particles are very fine (e.g. chalk powder in water)
   • Evaporation: removing water/solvent by heating; used to obtain dissolved solid from solution (e.g. salt from salt water)
   • Magnetic separation: using a magnet to separate magnetic materials from non-magnetic materials (e.g. iron filings from sawdust)
   • Churning: stirring vigorously to separate components (e.g. cream/butter from curd/milk)
   • Condensation: separating water vapour from a gaseous mixture by cooling (e.g. obtaining distilled water)
   • Choice of separation method depends on: nature of components, difference in physical properties, quantity of mixture
10. Living Creatures

    • Living beings vs non-living things: living beings move, eat (nutrition), grow, breathe (respiration), excrete, respond to stimuli, reproduce, and eventually die; absence of any feature indicates non-living
    • Movement in plants: not visible to naked eye (but occurs — roots grow downward, shoots grow upward)
    • Stimulus and response: living beings respond to changes in their environment (stimuli)
    • Excretion: removal of waste produced in the body by living beings
    • Seed germination: requires air (oxygen) and water in right amount; sunlight not essential for germination but excess water inhibits germination
    • During germination: roots grow downward (into soil), shoots grow upward (toward light); cotyledons provide initial nutrition
    • Plant life cycle: seed germination → seedling growth → adult plant → flowering → seed production → new seeds germinate; cycle continues
    • Animal life cycle: birth/hatching → growth stages → adult → reproduction → death; maintains continuity
    • Mosquito life cycle: egg → larva → pupa → adult (complete metamorphosis with four distinct stages)
    • Frog life cycle: egg → tadpole → froglet → adult (tadpole lives in water; adult is amphibian)
    • Metamorphosis: significant changes in body shape, structure, and sometimes habitat during life cycle stages (mosquito, frog)
    • Seeds are living (can germinate) — a potential misconception
11. Nature's Treasures

    • Natural resources: resources provided by nature required for survival — air, water, sunlight, forests, soil, rocks, minerals, fossil fuels
    • Human-made resources: created by humans to meet needs (e.g. machines, buildings)
    • Renewable resources: replenished by natural processes within a reasonable period (e.g. air, water, solar energy, forests — though forests take long to regenerate)
    • Non-renewable resources: limited quantities, not replenished within a reasonable period (e.g. coal, petroleum, natural gas — fossil fuels)
    • Air: mixture of gases including oxygen (essential for respiration of most living beings) and other gases; moving air is called wind
    • Composition of air: mainly nitrogen (~78%) and oxygen (~21%); also carbon dioxide, water vapour, dust particles in small amounts
    • Water: freshwater is limited; most is in oceans, glaciers, and ice (not directly usable); freshwater in ponds, rivers, lakes, wells is a small fraction
    • Water conservation: reducing wastage, rainwater harvesting (e.g. bawadi/stepwells in Rajasthan), preventing water pollution
    • Sun as the main source of energy on Earth: plants use solar energy for photosynthesis; all food chains begin with the Sun
    • Solar energy applications: solar panels (electricity), solar cooker, solar water heater, drying food
    • Forests: large areas of dense plant growth; habitat for diverse wildlife; provide food, shelter, oxygen, timber, medicinal plants; take very long to regenerate once lost
    • Fossil fuels: coal, petroleum, natural gas — formed from remains of ancient organisms over millions of years; non-renewable; major energy sources (cooking, transport, electricity generation)
    • Responsible use of natural resources: use judiciously, reduce wastage, prefer renewable options
12. Beyond Earth

    • Stars: self-luminous objects that emit their own light and heat; appear as bright points due to enormous distances from Earth
    • Sun is a star — nearest star to Earth (~150 million km); appears much larger than other stars because it is much closer
    • Constellations: apparent patterns formed by groups of stars (imaginary lines connecting stars); used for navigation historically; different cultures have different names
    • Key constellations introduced: Orion (seven stars forming a hunter shape; Sirius is nearby — brightest star in the night sky), Big Dipper (Saptarishi / Ursa Major — seven stars in a ladle shape), Little Dipper
    • Pole Star (Dhruv Tara): appears almost directly above Earth's North Pole; does not appear to move; used for finding north direction; not visible from the southern hemisphere
    • Solar system: the Sun and all objects revolving around it — includes eight planets, their moons, asteroids, and other objects
    • Eight planets in order from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
    • Inner four planets (rocky, smaller): Mercury, Venus, Earth, Mars; outer four (gas/ice giants, larger): Jupiter, Saturn, Uranus, Neptune
    • Planets do not emit own light; they reflect sunlight
    • Earth: Blue Planet (appears blue from space — due to water coverage); one rotation = ~24 hours (one day); one revolution around Sun = ~1 year
    • Venus: Morning/Evening Star (very bright; not a star); hotter than Mercury despite being farther — due to thick atmosphere trapping heat
    • Mars: Red Planet (reddish soil)
    • Moon: natural satellite of Earth; reflects sunlight; not self-luminous
    • Light pollution: excessive artificial light reducing visibility of night sky
    • Astronomical unit (au): distance from Earth to Sun (~150 million km), used for Solar System distances

It follows the NCERT Science textbook for Class 6 chapter by chapter, for 2026–27 — at this stage that textbook is the syllabus, since CBSE publishes none for Classes 6 to 8. Each chapter starts at the beginning, explains the idea in plain words, works an example before it asks a question, names the mistakes children actually make. Every question is worked out at the back, and the back matter carries a glossary of every term the book uses.

What it is not: an NCERT solutions book — it solves its own questions only; a question bank or sample-paper book; a coaching module or test series; a CBSE or NCERT publication; the school — no lab work, projects or internal-assessment help. It is not a workbook either — there is no space to write in it — and nothing in it needs a lab, an apparatus set, or anything you have to buy.

Free to read: these chapters open in any browser, with no account.

• Chapter 1: The Wonderful World of Science
• Chapter 4: Exploring Magnets