Curiosity

Chapter 1 'The Wonderful World of Science' introduces science as a way of thinking, observing and doing things to understand the world, and teaches the scientific method through everyday examples like a pen that stops writing.

• 1Science is defined as a way of thinking, observing and doing things to understand the world and uncover the secrets of the universe.
• 2Curiosity is the most important quality for science — it is also the title of the Class 6 NCERT Science textbook.
• 3The scientific method has five steps: observe something interesting, form a question, make a guess, test the guess through experiments or observations, and analyse the results.
• 4If the analysis shows the guess was wrong, a new guess is made and tested — the method is iterative, not linear.
• 5Science is compared to a 'giant and unending jigsaw puzzle' — every new discovery adds a piece but also generates more questions, so science has no final end.

Chapter 2 'Diversity in the Living World' of Class 6 Science (Curiosity) explores the variety of plants and animals around us, how they are grouped, the features that help them survive in different habitats, and why protecting biodiversity matters.

• 1Biodiversity refers to the variety of plants and animals found in a particular region; each member plays a different role in the ecosystem.
• 2Plants are grouped as herbs (soft green stems, small), shrubs (woody stems branching close to the ground), and trees (tall, hard thick woody stems with branches higher up).
• 3Climbers use support structures to grow upward; creepers grow along the ground.
• 4Venation is the pattern of veins on a leaf: reticulate venation (net-like, e.g. hibiscus) and parallel venation (e.g. banana, grass).
• 5Taproot system has one main root with side roots (e.g. mustard, chickpea); fibrous roots are a bunch of similar-sized thin roots from the stem base (e.g. grass, wheat).

Chapter 3 'Mindful Eating: A Path to a Healthy Body' from NCERT Class 6 Science (Curiosity) teaches students about food components (carbohydrates, proteins, fats, vitamins, minerals, roughage, and water), deficiency diseases, balanced diet, millets, food miles, and how to test nutrients in food.

• 1The Sanskrit saying 'annena jātāni jivanti' means 'food gives life to living beings'.
• 2Traditional food of any state is based on crops grown in that region, varying by soil, climate, culture, and traditions.
• 3Carbohydrates (wheat, rice, potato, banana) and fats (ghee, nuts, seeds) are energy-giving foods; fats store energy.
• 4Proteins (pulses, paneer, egg, fish) are body-building foods that help in growth and repair.
• 5Vitamins and minerals are protective nutrients required in small amounts; deficiency causes specific diseases.

Chapter 4 'Exploring Magnets' of NCERT Class 6 Science (Curiosity) introduces magnets, their poles, magnetic and non-magnetic materials, how a freely suspended magnet always points north-south, and the principles of attraction and repulsion between magnets.

• 1Naturally occurring magnets are called lodestones; modern magnets used in labs, toys, and pencil boxes are artificial magnets.
• 2Magnetic materials (iron, nickel, cobalt) are attracted towards a magnet; non-magnetic materials (wood, plastic, glass, rubber) are not.
• 3Every magnet has two poles — the North pole and the South pole — located at its ends, where magnetic force is strongest.
• 4Magnetic poles always exist in pairs. Breaking a magnet into smaller pieces always produces smaller magnets, each with both a North and South pole — a single pole (monopole) cannot exist.
• 5A freely suspended magnet always comes to rest along the north-south direction because Earth itself behaves like a giant magnet.

Chapter 5 of Class 6 Science (Curiosity) covers measurement of length using standard SI units (metre, centimetre, millimetre, kilometre) and introduces three types of motion — linear, circular, and oscillatory — along with the concept of a reference point.

• 1The SI unit of length is the metre (m); other units are kilometre (1 km = 1000 m), centimetre (1 m = 100 cm), and millimetre (1 cm = 10 mm).
• 2Body-part units like handspan (balisht) are non-standard because they differ from person to person, which is why SI units were adopted internationally.
• 3Ancient Indian units of length include angula (finger width), dhanusa, and yojana; angula is still used by traditional craftspeople.
• 4When using a scale: place it in contact with the object along its length; keep the eye directly above the measurement tip to avoid parallax error.
• 5If the zero end of a scale is broken, start at any clear mark and subtract that reading from the other-end reading to find the true length.

Chapter 6 'Materials Around Us' introduces Class 6 students to materials — substances used to make objects — and explores their properties including lustre, hardness, transparency, solubility, mass, and volume, leading to the definition of matter.

• 1A material is any substance used to create an object — examples include paper, wood, glass, metal, plastic, and clay.
• 2Classification is the method of arranging objects into groups based on a common property.
• 3Lustrous materials (e.g., metals like iron, copper, gold) have shiny surfaces; non-lustrous materials (e.g., paper, wood, rubber) do not.
• 4Hard materials resist compression and scratching (e.g., stone, iron); soft materials compress or scratch easily (e.g., eraser, sponge). Hardness is a relative property.
• 5Transparent materials allow clear vision through them (glass, water, air); opaque materials block vision completely (wood, cardboard, metals); translucent materials allow partial vision (frosted glass, butter paper).

Chapter 7 'Temperature and its Measurement' teaches Class 6 students what temperature is, how it is measured using clinical and laboratory thermometers, and the three scales — Celsius, Fahrenheit, and Kelvin — used to express it.

• 1Temperature is a reliable measure of the hotness or coldness of a body; our sense of touch can be misleading.
• 2A thermometer is a device used to measure temperature.
• 3The two common thermometers are the clinical thermometer (for body temperature) and the laboratory thermometer (for other purposes).
• 4Normal human body temperature is 37.0 °C (98.6 °F); it does not normally go below 35 °C or above 42 °C.
• 5Mercury thermometers have been replaced by digital thermometers because mercury is extremely toxic.

Chapter 8 'A Journey through States of Water' of Class 6 Science (Curiosity) explores the three states of water — solid (ice), liquid (water), and gaseous (water vapour) — and the processes of evaporation, condensation, melting, freezing, and the water cycle.

• 1Ice and water are the same substance — water — existing in different states (solid and liquid respectively).
• 2The three states of water are: solid (ice), liquid (water), and gaseous (water vapour).
• 3Evaporation is the conversion of water into its vapour state; it occurs continuously even at room temperature.
• 4Condensation is the conversion of water vapour into liquid water, occurring when vapour contacts a cold surface.
• 5Melting (solid → liquid) and freezing (liquid → solid) are opposite processes caused by heating or cooling.

Chapter 9 of Class 6 Science (Curiosity) covers the different methods used to separate mixtures in everyday life, including handpicking, threshing, winnowing, sieving, evaporation, sedimentation, decantation, filtration, churning, and magnetic separation.

• 1Handpicking separates substances from a mixture based on differences in size, colour, and shape; best when the component to be removed is in small quantities.
• 2Threshing separates grains from stalks by beating the stalks on a wooden log; modern threshers also perform winnowing simultaneously.
• 3Winnowing uses wind or blowing air to separate lighter husk from heavier grains; a soop (bamboo tray) is the traditional tool.
• 4Sieving is used for solid-solid mixtures with different particle sizes; fine flour passes through holes while larger particles like bran stay on the sieve.
• 5Evaporation converts a liquid into vapour, leaving behind a dissolved solid; used to obtain common salt from seawater kept in shallow pits.

Chapter 10 of Class 6 Science (Curiosity) explores what makes living creatures different from non-living things by examining eight key characteristics: movement, nutrition, growth, respiration, excretion, response to stimuli, reproduction, and death.

• 1All living beings share eight characteristics: movement, nutrition, growth, respiration, excretion, response to stimuli, reproduction, and death. Absence of any indicates a non-living thing.
• 2Breathing is part of respiration. Plants respire through tiny pores called stomata on the surface of leaves.
• 3Excretion is the removal of waste products. Sweat (water + salts) and urine are animal excretions; plants excrete excess water and minerals as droplets on leaves (e.g., grasses, roses).
• 4A stimulus is anything that prompts a living being to respond. Touch-me-not (chhui-mui) folds leaves when touched; amla tree leaves fold after sunset in response to changing light.
• 5Bean seed germination requires the right amount of water and air. Most seeds do NOT need light to germinate; sunlight is needed only for seedling growth after germination.

Chapter 11 'Nature's Treasures' of Class 6 Science (Curiosity) explores the key natural resources — air, water, solar energy, forests, soil, rocks, minerals, and fossil fuels — and teaches students how to classify, conserve, and use them responsibly.

• 1Air is a mixture of gases: nitrogen (78%), oxygen (21%), and argon, carbon dioxide and other gases (1%).
• 2We can survive without food or water for a few days but cannot survive without oxygen for even a few minutes.
• 3Moving air is called wind; windmills use wind energy to run flour mills, pump water, and generate electricity.
• 4Water covers about two-thirds of Earth's surface; most is saline ocean water not fit for use — freshwater is limited and precious.
• 5Rainwater harvesting (e.g., Bawadi stepwells in Rajasthan, Vav in Gujarat) is an age-old Indian practice to conserve water.

Chapter 12 'Beyond Earth' of Class 6 Science (Curiosity) introduces students to stars, constellations, the Solar System, the Moon, asteroids, comets, the Milky Way Galaxy, and the Universe.

• 1Constellations are defined sky regions often containing recognisable star patterns; the IAU officially listed 88 constellations.
• 2Star patterns were used for navigation before the magnetic compass; the Pole Star (Polaris/Dhruva tara) appears nearly stationary in the North and helps find direction.
• 3Sirius in Canis Major is the brightest star in the night sky; Orion (the hunter) is best viewed in India from December to April.
• 4The Sun is a star — a hot spherical ball of gases about 100 times bigger than Earth in diameter, located 150 million km (1 au) from Earth.
• 5The eight planets in order from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Inner four are small with rocky surfaces; outer four are giant gas-and-ice planets with ring structures.