The senses
The five main senses are sight, hearing, smell, taste and touch. Sense organs such as the eyes, ears, nose, tongue and skin collect information and send it to your brain.
Learning Wiki
Science
Living things, materials, forces, space and the human body.
Around ages 5–11
Primary
Weather
Weather is what the air is like at a particular place and time, such as hot or cold, wet or dry, windy or calm, sunny or cloudy. It changes from day to day.
Day and night
We have day and night because Earth spins once around every 24 hours. The side facing the Sun has daylight, and the side facing away is in darkness.
Parts of a plant
The main parts of a flowering plant are the roots, stem, leaves and flowers. Each part has a job, from soaking up water to making food and producing seeds.
Amphibians
Amphibians are cold-blooded animals with thin, moist skin that live part of their lives in water and part on land. Frogs, toads, newts and salamanders are amphibians.
Birds
Birds are warm-blooded animals with feathers, wings and a beak. They lay hard-shelled eggs, and most can fly. Penguins, ostriches and parrots are all birds.
Habitats
A habitat is the natural home of a living thing, where it finds the food, water, shelter and space it needs to survive.
Insects
Insects are small animals with six legs, three body parts and usually wings. Bees, ants, butterflies and beetles are insects. Spiders are not, because they have eight legs.
Living things
Living things are organisms that grow, feed, get rid of waste, sense the world and reproduce. Plants, animals, fungi and bacteria are all alive.
Reptiles
Reptiles are cold-blooded animals with dry, scaly skin. Snakes, lizards, turtles, tortoises and crocodiles are reptiles, and most of them lay eggs on land.
Teeth
Teeth bite, tear and grind food so it can be swallowed and digested. Children have 20 baby teeth, which are replaced by up to 32 adult teeth.
Dinosaurs
Dinosaurs were reptiles that lived on land from about 230 million years ago until most died out 66 million years ago. Birds are their living descendants.
Healthy eating
Healthy eating means eating a variety of foods from all the main food groups, with plenty of fruit and vegetables and water to drink, so your body gets everything it needs to grow.
Life cycles
A life cycle is the series of changes a living thing goes through from the start of its life to becoming an adult that can produce young, so the cycle begins again.
Magnets
A magnet is an object that pulls on certain metals, such as iron, and pushes or pulls on other magnets. Every magnet has a north pole and a south pole.
Mammals
Mammals are warm-blooded animals with hair or fur that feed their babies milk. Most give birth to live young. Humans, lions, whales and bats are all mammals.
Materials
Materials are what objects are made from, such as wood, metal, plastic and glass. Each has properties, like being hard, bendy, waterproof or see-through, that suit it to some jobs.
Shadows
A shadow is a dark area made when an opaque object blocks light. Because light travels in straight lines, it cannot bend round the object, leaving a dark shape behind it.
The human body
The human body is made of trillions of cells that form organs, such as the heart, lungs and brain. Organs work together in systems that keep you moving, breathing, eating and thinking.
The Sun
The Sun is a star at the centre of our solar system. It is a huge ball of hot gas that gives us light and heat, and it is about 150 million kilometres from Earth.
Forces
A force is a push or a pull. Forces can make things start moving, speed up, slow down, change direction or change shape. They are measured in newtons.
Seasons
Seasons happen because Earth is tilted. As Earth orbits the Sun over a year, each half of the planet takes turns leaning towards the Sun, getting more direct sunlight and longer days.
The Moon
The Moon is Earth's natural satellite, a rocky ball about a quarter of Earth's width that orbits us roughly once a month. It shines by reflecting sunlight.
The solar system
The solar system is the Sun and everything that orbits it, including eight planets, their moons, dwarf planets such as Pluto, asteroids and comets.
Evaporation
Evaporation is when a liquid slowly turns into a gas from its surface, like a puddle drying in the sun. It happens faster when it is warm, windy or the liquid is spread out.
Food chains
A food chain shows who eats whom in nature, starting with a plant that makes its own food and following the energy as it passes from one living thing to the next.
Hibernation and migration
Hibernation is a deep winter sleep that lets some animals save energy when food is scarce. Migration is a regular long trip to find food, warmth or a place to breed.
Melting and freezing
Melting is when a solid turns into a liquid as it heats up. Freezing is when a liquid turns into a solid as it cools. Water melts and freezes at 0 degrees Celsius.
Phases of the Moon
The Moon does not really change shape. As it orbits Earth, we see more or less of its sunlit half, which gives the phases from new moon to full moon and back in about 29.5 days.
Skeleton
The skeleton is the frame of bones inside your body. It holds you up, protects soft organs like the brain and heart, and works with muscles so you can move. Adults have 206 bones.
Skin
Skin is your body's largest organ. It covers and protects you, keeps water in and germs out, helps control your temperature and lets you feel touch.
The heart
The heart is a muscle about the size of your fist that pumps blood around your body, carrying oxygen and food to every cell and taking waste away.
The water cycle
The water cycle is the endless movement of water between the land, the sea and the sky. Water evaporates, condenses into clouds, falls as rain or snow and collects in rivers and oceans.
Vertebrates and invertebrates
Vertebrates are animals with a backbone, like fish, amphibians, reptiles, birds and mammals. Invertebrates have no backbone, like insects, spiders, snails, worms and jellyfish.
Friction
Friction is a force that acts when two surfaces rub or slide against each other. It slows things down and turns movement into heat, and it also stops us slipping.
Lungs
The lungs are two spongy organs in your chest that take oxygen from the air into your blood and remove carbon dioxide when you breathe out.
Rocks
Rocks are natural solids made of minerals. The three types are igneous (cooled melted rock), sedimentary (squashed layers of bits) and metamorphic (changed by heat and pressure).
Solids, liquids and gases
Solids, liquids and gases are the three main states of matter. Solids keep their shape, liquids flow and take the shape of their container, and gases spread out to fill any space.
Sound
Sound is made when something vibrates. The vibrations travel through air, water or solids to our ears. Sound cannot travel through empty space.
Electricity
Electricity is the flow of tiny charged particles called electrons through a material. It powers lights, phones and machines, and it can come from batteries or the mains supply.
Fossils
Fossils are the preserved remains or traces of plants and animals that lived long ago, usually found in sedimentary rock. They help scientists learn how life on Earth has changed.
Gravity
Gravity is the force that pulls objects towards each other. Earth's gravity pulls everything towards its centre, which is why things fall down and why the Moon orbits Earth.
Light
Light is a form of energy that travels in straight lines, very fast. We see things when light from them enters our eyes, either because they make light or because they reflect it.
Digestive system
The digestive system is the long tube and organs that break food down into tiny pieces your body can absorb for energy and growth, then get rid of what is left as waste.
Conductors and insulators
A conductor lets electricity or heat pass through easily, like copper. An insulator blocks it, like plastic or rubber. Metals are good conductors; most non-metals are insulators.
Metals
Metals are shiny, strong materials that conduct heat and electricity and can be hammered or stretched into shape. Iron, copper, gold and aluminium are metals.
Mixtures and solutions
A mixture is two or more substances mixed but not joined chemically. A solution is a mixture where one substance, like salt, dissolves completely in a liquid, like water.
Muscles
Muscles are bundles of stretchy tissue that pull to move your body, pump blood and push food along. They can only pull, so they often work in pairs.
Simple machines
Simple machines are basic tools that make jobs easier by changing the size or direction of a force. The six types are the lever, wheel and axle, pulley, ramp, wedge and screw.
Static electricity
Static electricity is a build-up of electric charge on an object, often from rubbing. It makes hair stand up, balloons stick to walls and, on a huge scale, lightning.
Electric circuits
An electric circuit is a complete loop that electricity flows around. A simple circuit has a battery, wires and a component like a bulb. If the loop is broken, the electricity stops.
Energy
Energy is what makes things happen: it makes things move, heat up, light up and grow. It cannot be created or destroyed, only changed from one form to another.
Heat and temperature
Temperature tells you how hot or cold something is. Heat is energy that flows from a hotter thing to a cooler one. They are linked, but they are not the same.
Space exploration
Space exploration began in 1957 with the first satellite, Sputnik 1. Since then people have orbited Earth, walked on the Moon and sent robots to planets, moons and beyond.
Stars
A star is a giant ball of hot, glowing gas that makes its own light. The Sun is our nearest star, and the others look like tiny points because they are so far away.
The brain
The brain is the control centre of your body. It sends and receives messages through your nerves so you can think, feel, move, remember and breathe.
Adaptation
An adaptation is a feature or behaviour that helps a living thing survive where it lives. A polar bear's thick fur and a cactus's spines are adaptations.
Blood
Blood is the red liquid pumped around your body by your heart. It carries oxygen and food to every cell, takes away waste and helps fight germs and heal wounds.
Ecosystems
An ecosystem is a community of living things and the non-living environment they share, such as a pond, a forest or a coral reef. All the parts depend on each other.
Layers of the Earth
Earth has four main layers: a thin rocky crust, a thick mantle of hot rock, a liquid outer core and a solid inner core. Each layer is hotter than the one above it.
Separating mixtures
Mixtures can be separated by using the different properties of their parts. Common methods are sieving, filtering, evaporation, magnets and chromatography.
Solar and lunar eclipses
An eclipse happens when the Sun, Earth and Moon line up. In a solar eclipse the Moon blocks the Sun; in a lunar eclipse Earth's shadow falls on the Moon.
Weathering and erosion
Weathering breaks rocks down into smaller pieces where they are. Erosion picks those pieces up and carries them away, by water, wind, ice or gravity. Then deposition drops them somewhere new.
Photosynthesis
Photosynthesis is how green plants make their own food. They use energy from sunlight to turn carbon dioxide from the air and water from the soil into sugar, giving out oxygen.
Plate tectonics
Plate tectonics is the idea that Earth's outer shell is broken into huge slabs called plates that slowly move. Where they meet, mountains rise and earthquakes and volcanoes happen.
Renewable energy
Renewable energy comes from sources that do not run out, such as sunlight, wind and flowing water. Using them makes electricity without burning fossil fuels.
The immune system
The immune system is your body's defence team. It stops germs getting in, finds the ones that do, and destroys them, using white blood cells, antibodies and protective barriers.
Around ages 11–16
Secondary
Physical and chemical changes
A physical change alters how a substance looks or its state but makes nothing new, like ice melting. A chemical change makes new substances, like wood burning to ash and smoke.
Evolution
Evolution is the way living things change over many generations. Individuals with features that help them survive tend to have more young, so those features become more common over time.
Black holes
A black hole is a place in space where gravity is so strong that nothing, not even light, can escape. Most form when a very massive star collapses at the end of its life.
Cells
A cell is the smallest living unit. Every living thing is made of one or more cells, each with a membrane, cytoplasm and, in plants and animals, a nucleus that controls it.
The rock cycle
The rock cycle is the slow, never-ending process in which rocks change from one type to another. Igneous, sedimentary and metamorphic rocks are melted, worn down, buried and squeezed into new rock.
Acids and bases
Acids are sour substances with a pH below 7, like lemon juice. Bases are slippery or bitter with a pH above 7, like soap. When an acid and a base react they neutralise each other.
Chemical reactions
In a chemical reaction, substances change into new substances with different properties. Burning, rusting, baking and cooking are chemical reactions.
Atoms
An atom is the tiny building block of all matter. It has a nucleus of protons and neutrons in the middle with electrons around it. The number of protons decides which element it is.
The periodic table
The periodic table is a chart of all 118 known chemical elements, arranged in order of atomic number. Elements in the same column have similar properties.
Elements, compounds and mixtures
An element has only one kind of atom. A compound is two or more elements chemically joined in a fixed ratio, like H₂O. A mixture is substances mixed but not joined, so they can be separated.
Density
Density is how much mass is packed into a volume. The formula is density = mass ÷ volume (ρ = m/V), measured in g/cm³ or kg/m³. Water's density is about 1 g/cm³.
Temperature conversion (Celsius, Fahrenheit, Kelvin)
To turn Celsius into Fahrenheit, multiply by 9/5 (1.8) and add 32. To turn Celsius into kelvin, add 273.15; to turn kelvin into Celsius, subtract 273.15.
Waves
A wave carries energy from place to place without carrying matter. Waves can be transverse or longitudinal, and wave speed = frequency × wavelength (v = fλ).
Inheritance and genetics
Inheritance is how characteristics pass from parents to children through genes. Each parent gives one copy of every chromosome, so you get one version of each gene from each parent.
Pressure
Pressure is force spread over an area, p = F ÷ A, measured in pascals (1 Pa = 1 N/m²). In a liquid it grows with depth, p = ρgh.
Acceleration
Acceleration is how quickly velocity changes. a = (v − u) ÷ t, the change in velocity divided by the time taken, measured in metres per second squared (m/s²).
Electrical power
Electrical power is how fast electricity transfers energy. P = V × I (watts = volts × amps), so a 230 V kettle drawing 10 A has a power of 2,300 W.
Exothermic and endothermic reactions
An exothermic reaction gives out heat, so the surroundings get warmer (like burning). An endothermic reaction takes in heat, so the surroundings get colder (like an instant cold pack).
Kinetic energy
Kinetic energy is the energy an object has because it is moving. The formula is KE = ½mv², with mass in kg and speed in m/s, and the answer is in joules (J).
Stopping distance
Stopping distance is how far a vehicle travels from the moment the driver sees a hazard until it stops. Stopping distance = thinking distance + braking distance.
Series and parallel circuits
In a series circuit everything is on one loop, so the current is the same everywhere and the voltage is shared. In a parallel circuit each branch gets the full voltage and the currents add up.
Electrolysis
Electrolysis uses electricity to split a compound that is melted or dissolved. Positive ions move to the negative electrode and negative ions to the positive one.
Enzymes
Enzymes are proteins that act as biological catalysts: they speed up chemical reactions in living things without being used up. Each one fits its own substrate, like a key in a lock.
Radioactivity
Radioactivity is when unstable atomic nuclei break down and give out radiation: alpha, beta or gamma. Half-life is the time it takes for half of the radioactive nuclei in a sample to decay.
Rates of reaction
The rate of reaction is how fast reactants are used up or products are made. Higher temperature, higher concentration, a bigger surface area and a catalyst all make reactions faster.
The electromagnetic spectrum
The electromagnetic spectrum is the whole family of electromagnetic waves: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays. All travel at the speed of light.
Momentum
Momentum is mass in motion: momentum = mass × velocity, p = mv, measured in kg m/s. It has a direction, and in a collision the total momentum stays the same.
The mole (amount of substance)
A mole is the chemist's counting unit: 6.02 × 10²³ particles. To find the number of moles, divide the mass by the molar mass: n = m ÷ M.
