Nature

The sun warms water in seas, lakes and puddles until tiny bits float up into the sky as invisible steam. Up high the air is cold, so the water gathers into clouds, and when the drops grow heavy enough they fall back down as rain.

A rainbow appears when sunlight shines through tiny raindrops still floating in the air. Each drop bends the light and splits it into many colours, so you see a big curved band of red, orange, yellow, green, blue and violet.

Sunlight looks white but it is really made of many colours mixed together. As it passes through the air, the blue part gets scattered and bounced all around the sky far more than the others, so when you look up the whole sky glows blue.

During a storm, a giant spark of lightning heats the air around it so fast that the air jumps apart with a huge bang. That bang is the thunder you hear, rolling and rumbling across the sky.

A seed is like a tiny lunchbox with a baby plant inside. When it gets water, warmth and soil, the baby plant wakes up, pushes a little root down and a green shoot up, and slowly grows toward the light.

Plants cannot go to the shop for food, so they make their own using sunlight. Their green leaves catch the light and mix it with water and air to make sugar, which is the plant's food and the reason it can grow.

Leaves are full of a green colour called chlorophyll, which is the part that catches sunlight to make the plant's food. There is so much of it that the whole leaf looks green to our eyes.

A flower's sweet smell is an invitation to bees, butterflies and other little visitors. The smell says come and taste my nectar, and while the visitors sip, they carry pollen from flower to flower and help new flowers grow.

Rain washes tiny bits of salt out of rocks and soil and carries them down rivers into the sea. The water later floats back up into the sky as rain, but the salt stays behind, so over a very long time the sea has become salty.

A cloud is made of millions of tiny water drops and ice bits, so small and light that they float in the air. When enough of them clump together and grow heavy, they fall as rain or snow.

After the rain, the sun warms each puddle and turns the water into invisible steam that floats up into the air. Little by little the puddle shrinks and dries, and the water it held is now on its way to becoming a cloud.

Snow is rain that froze high up in a very cold cloud. Instead of falling as drops, the water turns into tiny ice crystals that stick together into soft, white flakes and drift gently down.

As days get shorter and colder, many trees get ready to rest for winter. They stop feeding their leaves, the green fades to yellow, orange and red, and one by one the leaves let go and float to the ground.

A tree drinks water through its roots and sips sunlight through its leaves, and uses both to build new wood a little at a time. Year after year it grows taller and wider, and the biggest trees keep growing for hundreds of years.

Bark is the tough skin that wraps around a tree and keeps it safe. It protects the soft wood inside from cold, heat, insects and bumps, a bit like a coat and a shield rolled into one.

A single tree can be a whole neighbourhood. Birds build nests in the branches, squirrels dash along them, insects tuck into the bark, and moss and mushrooms settle on the trunk, all sharing one leafy home.

A volcano is an opening in the Earth's surface where hot, melted rock from deep underground can burst out. That glowing rock is called lava, and when it cools it hardens into new rock, slowly building the mountain taller.

The Earth's surface is cracked into giant pieces that fit together like a puzzle. These pieces move very slowly, and sometimes they get stuck and then suddenly slip, sending a shudder through the ground that we feel as an earthquake.

When two giant pieces of the Earth's surface push against each other, the land between them slowly crumples and folds upward, like a rug bunching when you push its ends. Over millions of years those wrinkles rise into tall mountains.

If you could dig straight down for a very long way, you would pass through cool rock, then hot melted rock, and finally reach a giant ball of metal at the centre. That middle part is hotter than the surface of a fire.

The sun heats some parts of the air more than others. Warm air rises and gets lighter, and cooler air rushes in to take its place. All that moving air, sliding from place to place, is the wind we feel.

A storm brews when warm, wet air rushes upward and builds a tall, dark cloud. Inside, water drops and ice crash around, and that busy churning can bring heavy rain, gusty wind, flashes of lightning and rolling thunder.

Inside a storm cloud, tiny bits of ice rub together and build up a huge amount of a kind of energy called electricity. When enough of it gathers, it leaps out in a giant spark, from cloud to cloud or down to the ground, as a flash of lightning.

The Earth is tilted a little as it circles the Sun all year. For part of the year your half of the world leans toward the Sun and gets warm summer days, and later it leans away and gets cold winter ones.

Water travels in a never-ending loop. The sun lifts it from seas and rivers into the sky, it gathers into clouds, falls as rain or snow, flows back to the sea, and then rises up to start all over again.

A river usually starts high up as rain or melting snow on a hill or mountain. Little trickles join into streams, streams join into bigger flows, and gravity pulls the water downhill all the way until it reaches a lake or the sea.

The oceans are a huge home for countless plants and animals, from tiny specks to giant whales. They also soak up heat to keep the world comfortable and send water into the sky that later falls as rain everywhere, even far from the sea.

The water from your tap usually starts as rain that collects in lakes, rivers or deep underground. It is cleaned to make it safe, then travels through big pipes all the way to your home, ready the moment you turn the tap.

Green leaves work like tiny kitchens. They take in sunlight, drink water from the roots and breathe in a gas from the air, then mix them together to make sugar for food. As they cook, they let out the fresh air that we breathe.

A food chain shows who eats what in nature. It often starts with a plant that makes its own food, then a small animal eats the plant, and a bigger animal eats that one. Energy from the sun passes along the chain link by link.

Soil is much more than plain dirt. It holds water and food that plants need to grow, and it is packed with tiny living things, worms, insects and creatures too small to see, that keep it healthy and full of life.

Every plant, animal and drop of water is connected, and people are part of that web too. When we keep the air, water and land clean and share space with wild things, nature stays healthy, and a healthy world takes care of us right back.

Weather is what the sky is doing right now, sunny, rainy or windy, and it can change from hour to hour. Climate is the usual pattern of weather in a place over many years. So a single cold day is weather, but a place being cold most winters is its climate.

Certain gases in the air act like a cosy blanket around the Earth. They let sunlight in to warm the ground, then trap some of that heat instead of letting it all escape back to space. This natural blanket keeps our planet warm enough for life. Without it, Earth would be frozen solid.

Over the last hundred years or so, people have burned huge amounts of coal, oil and gas for energy. That adds extra heat-trapping gases to the air, thickening the Earth's natural blanket, so the planet slowly warms. The good news is that people all over the world are working on cleaner ways to power our lives.

Nature keeps its own records. Deep layers of ice hold tiny bubbles of ancient air, tree rings show which years were wet or dry, and old rock and mud hold clues too. By reading these natural diaries, scientists can work out what the weather was like thousands of years before any thermometers existed.

The Earth is about four and a half billion years old, a number so huge it is almost impossible to picture. If all of that time were squeezed into one single day, humans would only appear in the last few seconds before midnight. Our planet has a very, very long story.

A fossil is the ancient remains or shape of a living thing turned to stone. When a plant or animal is buried in mud or sand, its soft parts usually rot away, but the hard parts like bones can slowly be replaced by minerals over millions of years. That leaves a stony copy for us to find.

We have never seen a living dinosaur, but they left plenty of evidence behind. Scientists dig up their fossil bones, eggs and footprints, then piece them together like a giant puzzle. By comparing them with animals alive today, they can work out how dinosaurs looked, moved and even what they ate.

The Earth's surface is broken into giant slabs that float on the hot, soft rock beneath, and they creep along incredibly slowly. Over millions of years this has pulled the continents into new positions. Long ago they were all joined in one huge landmass before drifting apart into the shapes we know.

The electricity in your home is made in power stations, often far away, then carried to you through wires. Some is made by burning fuels, but more and more comes from moving water, wind and sunlight. Whatever the source, the power travels along cables all the way to the plug in your wall.

The sun and wind are free, clean sources of energy that never run out. Solar panels soak up sunlight and turn it straight into electricity, while wind turbines use moving air to spin huge blades that generate power. Best of all, neither one adds heat-trapping gases to the air.

Coal, oil and gas are called fossil fuels because they formed from plants and tiny creatures that lived and died millions of years ago. Buried and squeezed for ages, they became fuels we can burn for energy. The trouble is that burning them adds heat-trapping gases to the air, which is why we are looking for cleaner choices.

Recycling means turning used things like paper, glass and plastic into new ones instead of throwing them away. It saves raw materials, uses less energy than making things from scratch, and keeps waste out of the ground and the sea. Small sorting choices at home add up to a big help for the planet.

A habitat is the natural home where a plant or animal has everything it needs to live, food, water, shelter and space. A pond is a habitat for frogs, a forest for owls, and even a single log can be a habitat for beetles. When a habitat is healthy, the living things in it can thrive.

Carbon is a building block found in every living thing, and it travels in a great loop. Plants take it from the air, animals eat the plants and breathe some back out, and it also moves in and out of the soil and the sea. This constant cycle keeps the same carbon moving between air, living things and the ground.

Rainforests are thick, green forests bursting with life, home to more kinds of plants and animals than anywhere else on land. Their trees make huge amounts of the fresh air we breathe and help keep the whole planet's weather steady. Protecting them protects countless creatures and helps everyone.

A food web is like many food chains woven together, showing how all the living things in a habitat are linked by what they eat. Most animals eat more than one thing and are eaten by more than one predator, so the connections cross over like a net. Change one strand, and the whole web feels it.