Day & Night

Earth is spinning all the time

The Sun lights only one side

How spinning makes day and night

Why sunrise and sunset look the way they do

Other planets have day and night too

Frequently asked questions

More lessons

• 👤 My Body Parts — Learn all the important parts of your body — head, arms, legs, and what each one does!
• 👁️ My Five Senses — See, hear, smell, taste and touch — your five senses connect you to the whole world!
• 🧼 Keeping Clean — Washing hands, brushing teeth, and bathing every day keeps germs away and keeps us healthy!
• 🐕 Pets and Farm Animals — Dogs, cats, cows, and hens — some animals live with us as pets or on farms to help us!
• 🦁 Wild Animals — Lions, elephants, tigers — wild animals live in forests and jungles far from our homes!
• 🦋 Birds and Insects — Parrots, sparrows, butterflies and bees — birds have wings and beaks, insects have six legs!
• 🌳 Types of Plants — Trees, shrubs, herbs, and climbers — plants come in many sizes and shapes all around us!
• 🌻 What Plants Need — Sunlight, water, soil, and air — plants need all four to grow big and strong!
• 🍎 Plants Give Us Food — Fruits, vegetables, grains, and pulses — so much of what we eat comes from plants!
• 🍽️ Meals of the Day — Breakfast, lunch, dinner and snacks — eating regular meals keeps us energetic all day!
• 🥦 Healthy Food Choices — Fruits, vegetables and milk keep us strong — choose healthy food over junk food!
• 🌾 Where Food Comes From — Food comes from plants, farmers, and animals — there is a long journey before food reaches our plate!
• ☀️ Day and Night Sky — The sun lights our day and the moon and stars shine at night — the sky is always changing!
• 🌤️ Types of Weather — Sunny, rainy, windy, cold — weather changes every day and tells us what to wear!
• 🌧️ Three Seasons — India has summer, monsoon, and winter — each season brings its own weather and fun!
• 👶 Growing Up — We grow from baby to child to adult — good food, sleep, and exercise help us grow strong!
• 💪 Our Bones and Muscles — 206 bones give us our shape and muscles move us — together they make every action possible!
• 🏃 Staying Healthy — Eat well, drink water, exercise, and sleep — four golden habits for a healthy body!
• 🐄 What Animals Eat — Herbivores eat plants, carnivores eat meat, and omnivores eat both!
• 🏠 Animal Houses — Birds build nests, rabbits dig burrows, lions live in dens — every animal has its own home!
• 🐣 Baby Animals — Some babies hatch from eggs, others are born alive — all are cared for by their mothers!
• 🌱 Seeds to Plants — A tiny seed holds a sleeping baby plant — water and warmth wake it up to grow!
• 🍃 Leaves and Roots — Leaves make food using sunlight and roots drink water from soil — together they keep the plant alive!
• 🌿 Plants Have Uses — Plants give us food, medicine, wood, cotton, and clean air to breathe — they are our most important resource!
• 🌊 Water Around Us — Water covers most of Earth — in oceans, rivers, lakes, rain, and underground wells!
• 💧 Uses of Water — We use water for drinking, cooking, cleaning, farming, and every living thing needs it to survive!
• 🚰 Saving Water — Only 3% of Earth's water is fresh — closing taps, short showers, and collecting rain all help save it!
• 💨 Air We Breathe — Air is all around us — we breathe in oxygen and breathe out carbon dioxide, and plants keep our air fresh!
• 🌬️ Wind and Storms — Wind is moving air — it can be a gentle breeze or a powerful storm, and it shapes our weather every day!
• ☁️ Clouds and Rain — Clouds form when water vapour rises and cools — and when they get heavy, they release rain that grows our food!
• 🌴 Plants in Habitats — Plants have amazing adaptations — cacti store water in deserts, lotus floats in ponds, and pine trees shed snow!
• 🌸 Flower Parts — Flowers have petals, sepals, stamens and a pistil — together they create seeds and new plants through pollination!
• 🍇 Seeds and Fruits — Fruits grow from flowers and carry seeds — seeds travel by wind, water, animals, and even explosion to grow new plants!
• 🕸️ Food Webs — Food chains show who eats whom — producers, consumers, and decomposers are all connected in a food web!
• 🦔 Animal Defences — Animals use camouflage, armour, spines, poison, speed, and even ink to protect themselves from predators!
• 🦋 Animal Life Cycles — Every animal goes through a life cycle — the butterfly changes from egg to caterpillar to pupa and finally a butterfly!
• ⚡ Food for Energy — Food gives us energy, builds our body, and protects us — carbohydrates, proteins, fats, vitamins, and water all have roles!
• 🍊 Vitamins and Minerals — Vitamins A, B, C, D and minerals like calcium and iron are essential for healthy eyes, bones, blood, and immunity!
• 🧼 Food Safety — Washing hands, covering food, and avoiding stale food protects us from germs and food poisoning!
• 🏔️ Water Sources — Water comes from rivers, lakes, groundwater, rain, and dams — it travels a long journey to reach our taps!
• 🔄 Water Cycle — Water evaporates from oceans, rises as vapour, forms clouds through condensation, and falls as rain — endlessly!
• 🚰 Safe Water — Not all water is safe — germs, chemicals, and sewage contaminate water, but boiling, filtering, and chlorination make it safe!
• 🌍 Air, Water and Soil — Air, water, and soil are the three pillars of our environment — all living things depend on them working together!
• 🏭 Types of Pollution — Air, water, and soil pollution harm all living things — factories, vehicles, and waste are the main causes!
• ♻️ Reduce, Reuse, Recycle — Reduce what we use, reuse what we have, and recycle what we can — together the three Rs protect our planet!
• 🧪 The Iodine Test — Find the hidden starch in your food.
• 🛡️ Tiny Protectors: Vitamins — A, B, C, D — what each vitamin does.
• 🥗 What's a Balanced Diet? — Build the perfect plate, food by food.
• 🚜 Food Miles: Farm to Plate — How does a chapati reach your kitchen?
• 🌾 Millets: Tiny Super Grains — Jowar, bajra and ragi — old and powerful.
• 🧲 Magnetic or Not? — Find out which everyday things a magnet can pull.
• 🧭 Two Poles, Two Rules — Why magnets sometimes snap and sometimes push apart.
• 🌍 Earth is a Giant Magnet — Why a compass needle always points north.
• 🛠️ Make Your Own Compass — Build a working compass with a needle and water.
• 🔧 Magnets in Everyday Life — The hidden magnets in things you use every day.
• 🤲 Hand-picking — Pick the bad bits out with your fingers.
• 🍚 Sieving — Separate small from big using a sieve.
• 🌾 Winnowing — Use wind to blow the lighter bits away.
• 💧 Cleaning Muddy Water — Sedimentation, decantation and filtration.
• 🧂 Evaporation — Get salt from saltwater by drying it out.
• 🧲 Magnetic Separation — Use a magnet to pull iron out of a mix.
• 🧊 Three States of Water — Solid, liquid, gas — all the same water.
• 🔥 Melting & Freezing — How ice and water swap places.
• 💨 Evaporation & Condensation — How water sneaks between liquid and gas.
• 🍳 Boiling — Water's fastest change — bubbles all the way through.
• 🌧️ The Water Cycle — How rain, rivers and clouds are all the same water.
• 🪐 The Eight Planets — A quick tour of our solar system.
• 🌗 Phases of the Moon — Why the Moon changes shape every night.
• ⭐ Stars & Constellations — Connect the dots in the night sky.
• ☄️ Comets, Meteors & Asteroids — The small visitors of the solar system.
• 🧱 Grouping Materials — Hard, soft, shiny, rough — every material tells a story.
• 🧂 Soluble and Insoluble — Some materials vanish in water. Others never do.
• 🔦 Transparent, Translucent & Opaque — Can light pass through? That's the question.
• 🌡️ What is Temperature? — The measure of how hot or cold something is.
• 🩺 Reading a Thermometer — Clinical, lab — how to read them right.
• 🌱 Living and Non-Living Things — What makes something truly alive?
• 🌵 How Plants Adapt — Different homes, different shapes — plants are clever.
• 🌍 Classifying Living Things — Fish, amphibians, birds — sorting life into kingdoms and groups.
• 🐫 How Animals Adapt — Humps, gills, and flippers — built for a reason.
• 🔭 What is Science? — Curiosity, observation, and the scientific way of thinking.
• 🧪 The Scientific Method — Observe, hypothesise, experiment, conclude — the scientist's recipe.
• 🔭 Science Tools & Measurement — Rulers, balances, cylinders — scientists don't guess, they measure.
• 📏 Units of Measurement — Metre, kilogram, second — the language of science.
• 📐 Measuring Length — From millimetres to kilometres — length has a unit for every scale.
• 🏃 Types of Motion — Straight, circular, back-and-forth, or random — motion comes in types.
• 🔬 The Cell — Basic Unit of Life — Zoom in on any living thing and find the same tiny unit.
• 🌿 How Plants Make Food — Sunlight, water, air — plants cook their own meals.
• 🫀 Organ Systems of the Body — Cells build tissues, tissues build organs, organs build systems.
• 🌳 What is a Forest? — More than trees — a whole living community of plants, animals and soil.
• 🌿 Why Forests Matter — Oxygen, water, climate — forests run the life-support system of Earth.
• 🌱 Save Our Forests — Deforestation, its consequences, and how we can protect what remains.
• 🐕 Super Senses — Dogs smell 10,000× better than us. Eagles see 8× sharper. Nature's senses are extraordinary.
• 🦇 Echolocation — Bats and dolphins navigate the dark using sound — a sonar system evolution built from scratch.
• 🐦 Animal Migration — The Arctic Tern flies 90,000 km every year — from pole to pole and back.
• 👁️ Our Five Senses — Your eyes, ears, nose, tongue and skin work together to build your picture of the world.
• 🍎 Digestion — Nine metres of tubing turns food into fuel — a complete guide to the digestive system.
• 🫙 Food Preservation — Why does food go bad — and how do we stop it? Freezing, drying, pickling and more.
• 🌱 Seed Germination — Inside every seed is a sleeping baby plant — here's how water wakes it up.
• 🌬️ Seed Dispersal — Dandelion fluff, coconuts and hooked burrs — how seeds travel far from their parent plant.
• 🌸 Parts of a Flower — Petals, stamens, pistils — every flower part has a job in making the next generation.
• 💧 Every Drop Counts — Only 1% of Earth's water is drinkable — water conservation matters more than ever.
• 🫧 Water Properties — Universal solvent, surface tension, capillarity — water's physics explain so much.
• 🚰 Clean Water — 5-step water treatment plant, boiling, SODIS, filtration — how to make water safe.
• 🌍 Earthquakes — Tectonic plates collide, slide and separate — the science of shaking ground.
• 🌡️ Blow Hot, Blow Cold — Heat always moves from hot to cold — through conduction, convection, and radiation.
• ⛽ What if it Finishes? — Coal, oil, and gas took 300 million years to form — we're burning them in decades.
• 🍎 Gravity — The invisible force that holds you to Earth, keeps the Moon orbiting, and holds the solar system together.
• 🧑‍🚀 Life in Space — In space, everything floats — sleep, food, water and all. Here's why and how astronauts cope.
• ⭐ Stars and the Sun — The Sun is a star — a giant ball of nuclear fire 109 Earths wide, 8 light-minutes away.
• 🌿 How Plants Grow — A seed becomes a tree using sunlight, water, and air — photosynthesis is nature's solar panel.
• 🐝 Bees and Flowers — Bees need flowers for food. Flowers need bees to make seeds. The perfect team.
• 🌳 Trees Are Homes — One tree can be home to hundreds of animals — birds, insects, squirrels and more.
• 🦔 Animal Homes — Birds build nests, bees build hives, rabbits dig burrows — every animal has its own home.
• 🦁 Who Eats Whom? — Grass feeds the rabbit, rabbit feeds the fox — nature's eating chain connects every living thing.
• 🐜 Amazing Ants — An ant can carry 50× its own weight. A colony of millions works like one giant brain.
• 🌧️ Rain and Rivers — Rain fills streams, streams fill rivers — rivers carry freshwater across the whole land.
• ♻️ The Water Cycle — Water evaporates, forms clouds, falls as rain, and flows back to the sea — endlessly.
• 💧 Save Every Drop — Only 3% of Earth's water is fresh — and most of that is frozen. Every drop we save matters.
• 🌾 Farm to Table — Before food reaches your plate, it travels through fields, factories, trucks, and shops.
• 🌈 Eat a Rainbow — Red tomatoes, orange carrots, green spinach — each colour gives your body something different.
• 🌱 Soil and Seeds — A handful of soil contains more living things than people on Earth — and seeds can wait decades to grow.
• 🦷 Teeth and Food — Your teeth are the first step in digestion — different teeth are shaped for different jobs.
• 💪 Bones and Muscles — 206 bones give your body its shape. Over 600 muscles pull those bones to create every movement.
• ❤️ Heart and Lungs — Your heart pumps blood to every cell, and your lungs fill that blood with the oxygen cells need.
• 🌸 Four Seasons — Spring, summer, autumn, winter — Earth's tilt as it orbits the Sun creates the four seasons.
• 🪨 Rocks and Soil — Rocks are not just stones — they are the raw material that becomes the soil all our food grows in.
• 🌙 Sun, Earth and Moon — Earth spins to give us day and night, orbits the Sun to give us a year, and the Moon follows along.
• 🌿 Photosynthesis — Plants convert sunlight, water and CO₂ into glucose — the foundation of almost all food on Earth.
• 🪴 Other Modes of Nutrition — Not all plants photosynthesise — parasites steal food, insectivores trap prey, and saprophytes eat the dead.
• 🌱 Replenishing Soil Nutrients — Crops deplete the soil — crop rotation, compost, and nitrogen-fixing bacteria keep it fertile.
• 🦁 Nutrition in Animals — Every animal must find, eat, and digest food — the strategies are as varied as life itself.
• 🦷 Animal Feeding Strategies — Sharp canines, flat molars, hooked beaks — every animal's teeth and jaws are shaped by what it eats.
• 🧫 Digestive Juices and Absorption — Your gut produces powerful enzymes that break any food into tiny molecules small enough to enter your bloodstream.
• 🌿 Natural Fibres — Cotton, silk, wool, and jute — fibres harvested from plants and animals that humans have woven for millennia.
• 🧪 Synthetic Fibres — Nylon, polyester, acrylic — fibres made in factories from petrochemicals that revolutionised clothing.
• 🪡 Fibre to Fabric — From raw fibre to finished cloth: spinning twists fibres into yarn, weaving interlocks them into fabric.
• 🌡️ Heat and Temperature — A teaspoon of boiling water and a bathtub of warm water — same temperature, very different amounts of heat.
• 🔥 Heat Transfer: Conduction — Metal feels cold even at room temperature — because it conducts heat away from your hand so fast.
• 🌊 Convection and Radiation — Sea breezes, boiling water, and the warmth of the Sun — heat travels in three very different ways.
• 🍋 Acids in Daily Life — Lemon juice, vinegar, fizzy drinks — acids are sour, corrosive, and all around us.
• 🧼 Bases and Alkalis — Soap, bleach, baking soda — bases are the opposites of acids and feel slippery to touch.
• ⚗️ Neutralisation and Salts — Mix an acid and a base and they cancel each other out — producing salt and water.
• 🔄 Physical Changes — Melting, dissolving, bending — physical changes alter shape or state but never create a new substance.
• ⚗️ Chemical Changes — Burning, rusting, cooking — chemical changes produce entirely new substances that cannot easily be reversed.
• 🟤 Rusting and Corrosion — Iron plus water plus oxygen equals rust — a slow chemical reaction destroying metal worldwide.
• ⛅ Weather and Climate — Weather changes daily; climate is what you expect — understanding both explains how life adapts.
• 📊 Reading Weather Data — Barometer, thermometer, rain gauge — meteorologists read these instruments to forecast tomorrow's weather.
• 🌍 Climate Adaptations — Camels store fat, polar bears have tiny ears, cacti spike their leaves — life finds ways to survive anywhere.
• 💨 How Wind Forms — Hot air rises, cool air rushes in — this simple principle drives everything from sea breezes to the monsoon.
• ⛈️ Thunderstorms and Lightning — A bolt of lightning carries a billion volts and reaches thirty thousand degrees — hotter than the Sun's surface.
• 🌀 Cyclones and Safety — At the eye of a cyclone it is eerily calm — but a wall of catastrophic winds surrounds it.
• 🌱 Soil Profile — Cut through the ground and you find distinct layers — each horizon tells a story of rock, time, and life.
• 🌊 Soil Erosion and Conservation — Rain, wind, and human activity strip topsoil that took a thousand years to form — but we can stop it.
• 🪱 Soil as a Habitat — A teaspoon of healthy soil contains more organisms than there are people on Earth.
• ⚡ What Is Respiration? — Every cell in your body burns glucose for energy — this chemical process is respiration, not breathing.
• 💪 Aerobic and Anaerobic Respiration — Sprinting flat out, your muscles run out of oxygen and switch to a less efficient backup — and that is what causes cramps.
• 🫁 Breathing in Animals — Fish breathe through gills, insects through spiracles, and your lungs have 700 million air sacs to maximise surface area.
• ❤️ The Circulatory System — Your heart beats 100,000 times a day, pumping blood through 100,000 km of vessels to every cell.
• 🌿 Plant Transport System — A tall tree moves hundreds of litres of water upward every day — with no pump, just physics.
• 💛 Lymph and Excretion — Beyond blood: the lymphatic system filters fluids and your kidneys clean 150 litres of blood every day.
• 🌿 Vegetative Reproduction — Strawberries send runners, potatoes grow from tubers, willows root from cuttings — no flowers needed.
• 🌸 Pollination and Fertilisation — A bee visits a flower and inadvertently delivers pollen that will become a seed — every fruit begins this way.
• 🌱 Seed Dispersal Methods — Dandelion seeds float on air, coconuts float on oceans, burdock hooks onto fur — plants evolved remarkable travel strategies.
• ⚡ Speed and Distance — Speed is simply distance divided by time — but understanding it unlocks all of mechanics.
• ⏱️ Measuring Time — From sundials to atomic clocks — measuring time precisely has driven science, navigation, and technology.
• 📈 Distance-Time Graphs — A line on a graph can tell the entire story of a journey — speed, stops, and direction changes at a glance.
• ⚡ Electric Circuits — Electricity needs a complete loop to flow — break it anywhere and the current stops instantly.
• 🔥 Heating Effect of Current — A light bulb glows because electricity makes its thin wire so hot it becomes white — resistance creates heat.
• 🧲 Magnetic Effect of Current — A live wire deflects a compass — every electric current creates a magnetic field around it.
• 💡 How Light Travels — Light races through space at 300,000 km per second — and always in perfectly straight lines.
• 🪞 Reflection of Light — When light bounces off a surface, the angle it arrives at always equals the angle it leaves — perfectly symmetrical.
• 🔍 Refraction and Lenses — Light bends when it moves from one material to another — and lenses use this bending to focus, magnify, or correct vision.
• 🌊 Water Distribution on Earth — Though 71% of Earth is covered in water, less than 1% is freshwater we can actually use.
• 🚿 Water Scarcity — Two billion people lack safe drinking water — understanding why helps us protect this finite resource.
• 💧 Groundwater and Conservation — Billions depend on underground water — but we're using it faster than rain can replenish it.
• 🌳 What Forests Give Us — Forests clean our air, regulate rainfall, prevent floods, and harbour most of life on land — yet we lose them rapidly.
• 🌿 Forest Biodiversity — A single hectare of tropical forest can hold more species than all of Europe — understanding this web of life reveals why forests matter.
• 🪓 Deforestation and Its Consequences — The world loses forest the size of a football field every second — and the consequences reach far beyond the trees themselves.
• 🚿 What Is Sewage? — Every tap we turn and toilet we flush creates wastewater — understanding what it contains explains why treatment is essential.
• 🔬 Wastewater Treatment — A sewage treatment plant cleans dirty water through a remarkable sequence of physical, biological, and chemical steps.
• 🚽 Sanitation for All — Access to a toilet and handwashing with soap are among the most powerful public health tools ever discovered.