DK Children’s Encyclopedia ( PDFDrive )

Feelings SEE ALSO
▸▸ Art p.28
Feelings are how we respond to things that happen in ▸▸ Brain p.45
and to us. Feelings affect our brains, bodies, and how ▸▸ Heart p.128
we behave. Being able to tell other people our feelings ▸▸ Language p.144
is important and helps us to feel connected to each other. ▸▸ Philosophy p.189
▸▸ Taste p.249

Disgusted Happy Sad
Disgust is a strong Chemicals are released If something bad
feeling of dislike for in the brain when we or disappointing
something we see, do things we like. The happens, we feel sad.
hear, smell, or taste. Sometimes we cry
chemicals make when we are sad.
us feel happy!

Scared Expressions Angry
If we are in danger we We get angry when
feel scared. Our heart The different faces we think something is
beats faster to help people use for unfair or wrong. Anger
makes our heart beat
us get away from feelings are called faster and our muscles
the situation. expressions.
tense up.
99

Film SEE ALSO
▸▸ Art p.28
A film, or movie, is a series of still images that are quickly
played one after the other, so that the pictures seem to ▸▸ Storytelling
move. Films are used to tell stories or show real events. pp.42–43
They were first invented in the late 1800s. Live action
films are recorded on cameras. Animations are usually ▸▸ Machines p.150
drawn by hand or on a computer.
▸▸ Photography
p.190

▸▸ Television p.251

▸▸ Theater p.253

E.T. the Extra-Terrestrial (1982) The Eagle Huntress (2016) Spy Kids (2001)

Film types

“Genre” is a French word
that means type. Films are
grouped into genres when
they have similar stories or
styles. Common genres
include action, science
fiction, and documentary.

2,000Around Science fiction Documentary Action
Sci-fi films explore themes of Documentaries are a record of real Action films are exciting stories
new films are made science and technology, such as life or actual events. They show about imaginary heroes or
in India every year. space. “Fiction” means imaginary, the wonders of nature and how heroines. They use their strength
and the science is often made up. people live. This was one of the and intelligence to stop people
The Wizard of Oz (1939) first film genres. from doing bad things.

Animation Silent films
Animated films bring drawings or models to
life on screen. Drawings are made by hand or Technology has come a
on a computer. Stop-motion is a long way since films were
type of animation that uses invented. The first films
models. The models are were in black and white,
photographed, moved, and and had no sound.
photographed again. Background music was
played live at the cinema,
and actors used their faces
and body gestures to tell
a story.

Musicals Charlie Chaplin in
These stories are told through A Dog’s Life (1918)
music, song, and dance. They
became popular in the 1930s,
when films were made with sound
and color for the first time.

My Neighbor Totoro (1988)
100

Fish SEE ALSO
▸▸ Life cycle p.146
Fish are animals that live in water. They are able to breathe
underwater, and have fins to help them swim around. ▸▸ Pets pp.152—153
There are more than 3,000 different
species of fish in the world. ▸▸ Oceans and seas
p.187

▸▸ Seashore p.220

▸▸ Vertebrates
p.266

The body is covered in Gills are special
plates made of thin organs that let fish
bone, called scales. breathe the gas
oxygen underwater.

Lionfish Fins steer the Goldfish
fish through
Long spines protect lionfish the water. Goldfish are the most
from other animals. popular pet fish. Newborn
They hunt at night, Deadly fins are used goldfish are shiny brown.
feeding on small to knock out other They turn golden when they
fish, crabs, sea animals. are a year old.
and shrimp.
Stinging tail Stingray Seahorse dad
Red lionfish has one or two
poisonous spikes. These fish are found Most fish don’t look after
Morays have a in warm, shallow their eggs. Seahorses are
poisonous bite. Blue spots let other waters. Most of their different—the male carries
fish know that the time is spent buried the eggs around in a pouch
Eel stingray is deadly. in the sand, waiting on its belly, until they hatch.
to pounce on other
Eels are long fish that look sea animals.
like snakes. They have more
than 100 bones in their spine,
which makes them very bendy.

Zebra moray eel Blue spotted stingray
101

Flags SEE ALSO
▸▸ Africa p.12
A flag is a piece of material showing a unique set of colors
and symbols. Flags represent a country, city, religion, ▸▸ Color pp.26–27
organization, or sport. The symbols and colors can also
represent a message, such as a request for help. Flags ▸▸ Asia p.29
are often flown from flagpoles outside buildings to
show who the building belongs to. ▸▸ Governments
p.123
National flags
▸▸ North America
Each country has its own special flag, p.184
called a national flag. Most of these
have colors or stripes with stars or other ▸▸ World p.275
symbols placed on top. Each part says
something about the country.

China USA
Red stands for communism, which is The stars stand for the 50 US
the type of government in China. states. The stripes are for the
The stars show communism and original 13 states. The flag is
Chinese unity. nicknamed “the stars and stripes.”

United Kingdom Germany India
The upright red cross and The black, red, and The colors stand
the diagonal red and white gold are from the for ideas such as
crosses show the English, uniforms of German peace and truth.
Northern Irish, and Scottish soldiers in the 1800s. The central wheel
flags of the United Kingdom. symbol is from the
The first national Buddhist religion.
Kenya flag was flown in
The shield is a sign of Signal flags
the Maasai people of 1478Denmark in
Kenya. The color white . Flags can be used to send messages.
represents peace. Ships use flags to ask for help if they are
102 in trouble, or to tell other ships to keep
out of the way.

“I need help”

“I need “Keep clear
a pilot” of me”

Flowers SEE ALSO
▸▸ Fruit and seeds
Flowers are a part of a plant. To make new seeds,
they swap tiny grains called pollen. Pollen can p.115
be spread by wind or insects. Flowers have brightly ▸▸ Habitats p.126
colored petals to attract insects. ▸▸ Insects p.134
▸▸ Plants p.194
Flower structure Stigma ▸▸ Shapes p.222
This is sticky to ▸▸ Trees p.261
Flowers have male and female catch any pollen
parts. To make a seed, pollen that is carried Anthers
passes from the male part of to the flower. These are the male
one flower to the female parts of the flower.
part of another. They are covered in
tiny grains of pollen.

Petals Ovary Filament
These are This is the female part This stalk
brightly colored of the flower where holds up
to attract insects new seeds form. the anther.
to the flower.
The tallest flower
Insects
is the Titan arum.
Insects help to move pollen from the anther
of one flower to the stigma of another. The pollen It grows more than
travels on their bodies. Once transferred, the
pollen fertilizes the ovary to form seeds. 10 ft (3 m) high.

Flower shapes Dome

Different shapes of flowers attract
different insects. Some insects fit
down long, narrow flowers, others
need big petals to land on.

Cone-shaped Regular Rosette Bell-shaped
103

The story of... Ribs with black-
eyed peas and
Eating collard greens,
from the US
When we eat, we take in all the things we
need to keep us alive and healthy. Eating
food gives us the energy that allows
us to think, walk, play, and work.
It is also something
we love to do.

Paella from
Spain

Food around the world

People used to only eat things
that were grown near them.
Now, we can eat food from all over
the world. Different countries

have their own special
recipes to make their

favorite foods.

Pizza from Italy

Kebabs
from Turkey

Dosa from India

104

Early eating Food allergies

Our ancient ancestors Some people are allergic to
hunted for meat and fish, certain foods, which means
and foraged for fruit, nuts, they become ill when they eat
and roots. They started them. These foods can include
using fire to cook food
shellfish, peanuts, and
around 400,000 milk-based foods.
years ago.

Fire

Chow mein 1.3More than Peanuts
from China
billion people

in the world work

as farmers.

Bento box Farming
from Japan
People began farming at
least 15,000 years ago. Today,
almost half of the world’s land is
farmed for food. Farmers breed
animals for their meat, milk, and

eggs. They also grow plants
called crops, such as
wheat and oats.

Combine harvester cutting wheat

Insect protein Edible Eating in space
mealworms
Insects such as mealworms Astronaut space food must
and caterpillars are eaten be easy to eat, light in weight,
all over the world. They don’t quick to prepare, and not too
need a lot of space to grow, so messy. Food is often freeze-
they are an environmentally
dried and put in pouches.
friendly alternative to Water is then added
farmed meat. before eating.

Astronaut food

105

Food SEE ALSO
▸▸ Digestion p.79
Humans need to eat the right mixture of different food ▸▸ Energy pp.88–89
groups to keep all the parts of the body working properly. ▸▸ Eating
Food gives us energy to move, grow, and repair our
bodies. Types of food give our bodies the different pp.104–105
goodness we need. ▸▸ Food chains

Food groups p.107
▸▸ Gases p.117
There are five main food ▸▸ Plants p.194
groups that give us the
nutrients and vitamins Carbohydrates
we need to be healthy. Bread, rice, cereal,
and pasta contain
carbohydrates, which
give our bodies energy.

Dairy foods
Milk, yogurt,
cheese, and butter
contain calcium to
help teeth, nails,
and bones grow.

Fruit and Protein
vegetables Meat, fish, eggs,
Fruit and and beans are
vegetables have high in protein,
fiber, which helps which is needed
break down our food. to grow and
They also contain repair our bodies.
vitamins and minerals
that help our bodies
work properly.

Drinking

Water transports the
goodness we get from food
into and around our body.
It then flushes waste materials
out of our bodies.

Fat and sugar Energy
Sugar and fat give our
bodies energy. We can When we eat, our body
get fat from food like changes energy in food into
cheese and nuts, and the energy we need to move
sugars from fruits. and grow. Stored energy is
Too much fat and turned into movement
sugar is bad for us. energy in our bodies.

106

Food chains SEE ALSO
▸▸ Animal groups
A food chain is the passing along of energy from food.
Only plants can make their own food. All animals are part p.22
of a food chain, either eating plants or other animals.
All animals need energy to grow, survive, and reproduce. ▸▸ Conservation p.72

Energy on the move ▸▸ Eating pp.104—105

Energy moves along a food chain. Each animal ▸▸ Food p.106
in the chain gets energy from what it eats. The
arrows show how the food energy is passed along. ▸▸ Habitats p.126

▸▸ Photosynthesis
p.191

Producer Primary consumer Secondary consumer Decomposer
Plants produce their own food Animals that eat plants Meat-eating animals that These animals break down
by a process using light from are called primary eat plant-eaters are called decaying material, such as
the sun. In a food chain, they consumers. They are secondary consumers. They dung, returning the goodness
are called the producers. also called herbivores. are also known as carnivores. to the soil for plants to use.

Food web Swarms could Plant Plenty of plants means Plenty of plant-
eat too many there can be plenty of eaters means
Animals don’t just feed plants and plant-eaters. meat-eaters
on a single type of plant affect other can survive.
or animal, so food chains plant-eaters.
become food webs. These
can show how energy Antelope
is passed around a
whole habitat.

Carnivores eat a Grasshopper
great variety of food
to survive. Meerkats
eat grasshoppers,
scorpions, and
other small animals.

Meerkat Scorpion
Lion
Tertiary consumer Martial eagle Dung
If food energy has been beetle
transferred three times,
the animal is called a
tertiary consumer.

107

Forces SEE ALSO
▸▸ Friction p.114
A force is a push or a pull. Forces can start things moving, ▸▸ Gravity p.125
speed them up, or slow them down. Some forces work ▸▸ Magnets p.151
through touching. Others, such as gravity, work invisibly ▸▸ Measuring p.159
and can affect objects a long way away. ▸▸ Solar system

p.233
▸▸ Sun p.247

Pushing force A push away Gravity
from the hand.
A pushing force makes things start to move Gravity pulls objects down
and can also speed them up. Your hand applies toward the Earth. It’s the
a pushing force when it moves a toy car. force that stops us from
floating off into space.

Gravity
pulls the
ball down.

Pulling force A pull toward Magnetism
the hand.
A pulling force also makes Magnetism is a force that
things start to move. It moves pulls objects toward a
things forward from where magnet, or pushes them
the force is coming. away. Opposite magnetic
forces attract each other.

+— +—

The magnets
pull together.

Friction

Balanced forces Friction Engine power Friction is a force that
pulls the car pushes the slows down movement.
Pushes and pulls can act backward. car forward.
in different directions at It is created when two
the same time. If they When you sit still surfaces touch.
are balanced, the object
moves at a steady in a chair, the forces Muscles
speed, or is still. If one power the
force is bigger, the object on you are perfectly leg forward.
gets faster or slower.
balanced.
Friction drags
Gravity pulls the leg backward.
the car down.

108

Forests SEE ALSO
▸▸ Animal homes p.23
Forests are places where many trees grow. Forests grow
in a wide range of places all over the world. There are ▸▸ Fruit and seeds
different types, depending on the temperature and how p.115
much rain they get. Different trees, plants, and animals
live in each type of forest. ▸▸ North America
p.184

▸▸ Rain forests p.204

▸▸ Seasons p.221

▸▸ Trees p.261

Deciduous forests Silver birch Coniferous forests Black-capped
trees have chickadees
These forests have four seasons, with warm silvery bark on These forests are found in cold, northern nest in rotting
summers and cold winters. Many trees drop their trunk. parts of the world. The trees have needlelike tree stumps.
their leaves in autumn and grow them back leaves. Their branches slope so that any snow
in spring. These are called deciduous trees. slides off. These are called coniferous trees.

Beech trees Oak trees can Spruce trees have Jack pines
produce spiky live for hundreds sharp-tipped, have seeds in
beechnuts of years. prickly needles. structures called
in autumn. pine cones.
Grey wolves
White-backed grow thick
woodpeckers fur in winter.
peck holes in
trees to find food
and make nests.

Brown bears are Black bears can
one of the world’s climb trees.
largest meat-eaters.

Ferns grow in Red foxes have bushy Snowshoe hares Moose grow new
damp, shady tails to help them grow thick white antlers every year.
places. balance and keep warm. fur in winter.
Spruce grouses search
Fungi live on Wild boars dig Beavers build their the forest floor for
damp, rotting wood. with their snout homes from tree trunks. needles to eat.
to find food.
Dead wood provides
food and shelter for Polish forest Lichens grow Canadian forest
small animals. This large area of on rocks and These forests are covered in
forest is home to many tree trunks. snow for most of the year. The
Common shrews eat many animals. Parts of the plants and animals that live here
small animals each day. forest are protected, to must be able to survive the cold.
keep them as they are.

109

Fossil fuels SEE ALSO
▸▸ Carbon cycle p.49
Fossil fuels are natural materials that formed underground ▸▸ Climate change
millions of years ago. We dig them up or pump them out
of the ground so that we can burn them to make energy p.60
to power vehicles or to make electricity. There are three ▸▸ Dinosaurs p.80
types of fossil fuel: coal, crude oil, and natural gas. ▸▸ Fossils p.111
▸▸ Industrial
How fossil fuels form
Revolution p.133
Fossil fuels are made from dead sea ▸▸ Pollution p.198
creatures and rotten plants. These
materials are buried deep under layers Coal
of rock and soil that have built up over
time. Heat and the weight of the Coal is dug from mines
that extend deep
ground above change them into underground, or
fossil fuels. from gigantic open
pits at the surface.

1. Rotting 2. Heat and weight 3. Compression
Dead trees rot away As they are buried The remains are
and are buried in mud. deeper, the remains are compressed (squeezed)
heated and squeezed. into a layer of coal, which
is called a seam.

Generating Gas and oil
electricity
Crude oil is extracted from the
Fossil fuels are burned in earth by drilling. It is used to
power stations to make power vehicles and make
electricity. We have used plastics. Gas is also released
fossil fuels to make through drilling. It is used for
electricity for many years, heating buildings. There are
but burning them harms limited amounts of fossil fuels —
the environment. if we keep using them, they will
eventually run out.
Cooling towers at a
power station. 110

Fossils SEE ALSO
▸▸ Dinosaurs p.80
Fossils are the remains of plants and animals from long ▸▸ Fossil fuels p.110
ago. They are usually bones or shells that have turned into ▸▸ Prehistoric life
stone. Some fossils are so small that we cannot see them
without special equipment. Others are as tall as a building. p.202
▸▸ Rock cycle p.213
▸▸ Skeleton p.228

The best fossils This dinosaur’s We only know
are found in very sharp teeth tell
fine-grained rock. us that it was that dinosaurs
a meat-eater.
Dinosaur fossil existed because we
have found their
Sometimes whole animals
can be found as fossils. This fossil remains.
skeleton belonged to a small
dinosaur named Coelophysis
(SEE-low-FY-sis).

Complete fossil
skeletons like
this one are
very rare.

How fossils 147 million years ago 100 million years ago 2 million years ago 5 years ago
are made
Death Burial Turning to stone Discovery
To become a fossil, A dinosaur dies and its Layers of mud, sand, and The skeleton of the Millions of years later,
an animal or plant body sinks into the soft ash cover the dinosaur, dinosaur slowly turns a scientist uncovers
needs to be covered mud by a river. and its flesh rots away. from bone to stone. the fossil skeleton.
up soon after it
dies. Turning into 111
a fossil takes
millions of years.

Fractions SEE ALSO
▸▸ Astronomy p.32
Fractions are parts of whole numbers. They are written as ▸▸ Clocks p.61
one number over another number. The number on the top ▸▸ Measuring p.159
is usually smaller than the one on the bottom. Fractions ▸▸ Numbers p.185
can be used on their own or with whole numbers. ▸▸ Shapes p.222
▸▸ Symmetry p.248

Common 1 1 Quarter
fractions 2 4 A quarter is 1 part
out of 4 equal parts.
A whole number can 1
be split into any 8 Eighth
number of parts to One-eighth is 1 part
make a fraction. out of 8 equal parts.
Here are some of
the fractions we
use most often.

Half
Half of a number is
when it is split into
two equal parts.

Parts of a fraction Decimals Same but different?

The top number in a fraction is Fractions can also be written as Fractions can be written differently
called the numerator. The bottom decimals. The number to the left of the but mean the same. A half is the
number is called the denominator. decimal point is a whole number. The same amount as two quarters.
They are divided by a line. number to the right is the fraction.
One half (1⁄2)
3 The numerator 0.75 This number is
4 The denominator the fraction. Two-quarters (2⁄4)
Decimal
Three-quarters The decimal point
divides the whole
number from
the fraction.

112

French Revolution SEE ALSO
▸▸ Buildings p.48
For years, France was ruled by all-powerful kings, ▸▸ Money p.69
who were very rich and could do whatever they ▸▸ Europe p.94
wanted. The ordinary people of France were poor. ▸▸ Governments
Between 1789 and 1799, the people overthrew the
king and changed laws. p.123
▸▸ Law p.145
▸▸ War pp.278–279

Marie Antoinette The Bastille
was used to
The luxurious lifestyle of keep prisoners
Marie Antoinette, the of the king.
French queen, made
many ordinary people Louis was
angry. They thought beheaded using
she did not care a machine called
about their the guillotine.
problems.

The Bastille

The Bastille was a royal prison in Paris. On

July 14, 1789, a crowd attacked it and stole

weapons that had been stored inside.

King Louis XVI General Antoine-Joseph
was killed Santerre was a leader in
in 1793. the Revolution.

End of the monarchy

The king and queen tried to run
away from France dressed as
servants. They were caught
and later executed in front of
crowds of people.

113

Friction SEE ALSO
▸▸ Forces p.108
Friction is a force that slows down moving things by pulling
against the direction of their movement. It is created ▸▸ Water
between two surfaces as they move past each other. pp.120–121
Different surfaces produce different amounts of friction.
▸▸ Gravity p.125

▸▸ Materials p.157

▸▸ Temperature
p.252

Grip or slip? Producing heat

Rough surfaces grip better because If we rub our hands
they create more friction than smooth together there is friction
surfaces. Smooth surfaces slip past between them. They start
each other because they create less to get warm because
friction than rough surfaces. friction produces heat.

Rubber sole
Snow boots have rough
rubber soles that grip,
so that the climber’s
feet don’t slip.

Rubber grip on Smooth bottom
snow boots of the ski

Icy surface Icy surface
Lots of friction Not much friction
The icy surface and the The snow and the ski have
sole of the boot have lots little friction between them
of friction between them. and the ski slides easily.

Skis
Smooth skis slide over
an icy surface very
easily. They are made
of many different
materials, including
wood and plastic.

114

Fruit and seeds SEE ALSO
▸▸ Animal groups
Seeds store everything a new plant needs to start
growing, including food. A fruit protects the seeds p.22
inside it. It also gives a plant a way to move its seeds ▸▸ Flowers p.103
away to somewhere they can grow. ▸▸ Eating

Fruit pp.104–105
▸▸ Plants p.194
Fruit forms from the flowers of ▸▸ Trees p.261
some plants. Fruit usually tastes ▸▸ Weather p.271
sweet, so people and animals
like to eat it. Spreading seeds

Plants spread, or
disperse, their seeds
in different ways.

Apple seeds
sit in a core in
the middle of
the fruit.

Apple seeds Apple Peapod By wind
Some plants have “winged”
can take up to seeds that help their seeds
fly away in the wind.
80 days
By animal
to begin to grow. Animals eat fruit, and then
poop out the seeds away
Peas are the seeds Leaves start from the plant.
inside a peapod. to make food
for the plant. Exploding pods
How seeds grow Some plants have seed pods
Leaves unfold that explode, flinging the
and shoot seeds into the air.
straightens.

Many plants grow from seeds. With Shoot bursts
water, the right temperature, and soil, through the soil.
a seed can begin to grow into a plant.

Bean seed Roots grow Shoot begins
starts to to anchor to grow
swell. the plant upward,
in the soil. toward
the light.

115

Galaxies SEE ALSO
▸▸ Gases p.117
Galaxies are enormous groups of stars, planets, dust, and ▸▸ Milky Way p.167
gas that are held together by the force of gravity. They ▸▸ Physics p.192
come in different sizes and shapes, including spiral, ▸▸ Shapes p.222
elliptical, and irregular. ▸▸ Stars p.242
▸▸ Universe p.263

New stars form Spiral galaxy
in the spiral
arms. Spiral galaxies are disk-shaped with
spiral arms. They are the most
common type of galaxy. On
average, they contain
more than 100 billion
stars. Our Milky
Way is a spiral
galaxy.

Scientist think All stars The middle of the
that galaxies are rotate around galaxy bulges
mostly made of the center of outward.
a material called the galaxy.

“dark matter,” Irregular galaxy

which we can’t see. Small galaxies that do
not have a clear structure
Elliptical galaxy are known as irregular
galaxies. These may be
Elliptical galaxies are created by two galaxies
rounded in shape, and colliding. They contain
are usually made up of lots of young stars,
older stars. They are dust, and gas.
generally larger than
spiral galaxies. Elliptical 116
galaxies contain lots of
stars but little gas or dust.

Gases SEE ALSO
▸▸ Changing states
Gases are all around us—we are surrounded by a
mixture of gas called air. We can keep them in sealed p.57
containers but if we open the container, the gas ▸▸ Elements p.90
escapes and spreads out. Most gases are invisible. ▸▸ Liquids p.148
▸▸ Lungs p.149
What gases do Helium is a ▸▸ Mixtures p.168
lighter gas than ▸▸ Solids p.234
Gases have things they air, so helium
do called properties. For balloons float. Blowing bubbles
example, gases can be
squashed and then they Soap bubbles contain a little
push back to fill the original bit of air that pushes out
space. This is useful for toward the bubble. The soap
pumping up bike tires bubble mix is stretched but
that cushion bumps in pushes back, squashing the
the road as we ride. air into a sphere.

Gases
expand
to fill their
container.

Gas would Fizzy drinks
escape from an
unsealed container. When you see bubbles in a
liquid, every one of them is
full of gas. In a fizzy drink,
the bubbles are the gas
carbon dioxide.

Gas particles What’s in air? 78% 1% other gases
Gases are made from tiny nitrogen 21% oxygen
particles that move away Air is the gas all around
from each other in all us. It is made of a The gases in air
directions at top speed. mixture of different
They travel long distances gases, but mostly a
unless they bounce off gas called nitrogen.
solid barriers. We breathe in oxygen
from the air for our
bodies to use.

117

Gemstones SEE ALSO
▸▸ Elements p.90
Gemstones are minerals that can be cut and polished
to make jewels. They are often set in pieces of jewelry, ▸▸ Metals p.162
such as rings, brooches, and even crowns. Many gemstones,
such as rubies, are brightly colored. Others, such as ▸▸ Money p.169
diamonds, are usually colorless.
▸▸ Precious metals
p.199

▸▸ Gold pp.200–201

▸▸ Rocks and
minerals p.214

Cutting gemstones Cut ruby Jewelry

Gemstones are found Gems are often set
as minerals. To become in precious metals,
sparkly jewels, they must such as gold and silver.
be cut into shape. Very They are used to
sharp tools are used to make brooches,
carefully cut the stone into earrings, and other
exactly the right shape. pieces of jewelry.

H l Uncut ruby Some gemstones,
Red opa Pink ruby such as types of
essonite garnet The small diamond, are worth
sides made a lot of money.
Purple amethyst by cutting are Blue diamond
called facets. re Smithsonite
Red ruby
Blue sapphi Emerald

Spessa rtine garnet Sugilite The sparkliest
gems have the
Garnet most facets.

Lolite Tur quoise

Different colors This rectangular Topaz Tourmaline
shape is called
The colors of gemstones a step cut. Unusual
are often caused by shapes, such
substances in minerals Diamonds as this heart,
known as impurities. are called
Sapphires and rubies are are made entirely from fancy cuts.
both types of a mineral
called corundum, with carbon squeezed
impurities that make
them blue or red. under enormous

pressure deep

within the Earth.

118

Genes SEE ALSO
▸▸ Body cells p.41
Genes are the instructions that make people the way they ▸▸ Evolution p.95
are. They include things like skin color, hair color, and ▸▸ Human body
height. Half our genes come from our mother and half
from our father. p.130
▸▸ Life cycle p.146
Inheritance ▸▸ Mammals p.154
▸▸ The sciences
Face shape, eye color, and
hair texture are passed pp.218–219
down from either the
mother’s or the father’s If you unraveled
genes. Skin color works
differently—it depends on all the DNA in a
the amount of a chemical
called melanin in the skin. person it would reach
to the sun and back

400 times!

Her hair is Mother Father Her hair is curly
light brown like her mom’s,
and straight His eyes are His hair is black and light brown
like her dad’s. brown like and curly like like her dad’s.
his mom’s. his mom’s.
Her face shape
was passed
on from her
mother’s genes.

Child 1 Child 2 Child 3 Her skin color
could be the
Clones same as either
parent or
Most animals get a mix of anything in
different genes from their between.
parents. Clones have
exactly the same genes as What is DNA?
another animal. Dolly the
sheep was the first cloned Genes are made from long structures
mammal. Her genes were called DNA. Everyone has different DNA,
taken from a single cell of except for identical twins, whose DNA
a female sheep. is the same.

DNA looks like a
twisted ladder.

119

The story of... Blue planet

Water Nearly three-quarters of the
Earth is covered by oceans and
Water is a clear, colorless substance that is seas. Rivers and lakes stretch
found all around us. It forms Earth’s oceans,
lakes and rivers, snow and ice, and the clouds across the land’s surface.
drifting overhead. All living things—including The polar regions, near the North
us—are mostly made of water, so without it
our planet would be lifeless. and South Poles, lie beneath
frozen water, ice, and snow.

h
Planet Eart
More than 96 percent
What’s in water? of all the water on
Earth’s surface is too
Water is made up of tiny salty to drink.
particles called molecules. Each
one has an oxygen (O) atom joined
to two smaller hydrogen (H) atoms,
so water is also known as H2O.

O Fish breathe using
H
special organs
called gills to

extract oxygen from
the water.

Water H
molecule

Hydroelectric dam Water power About 90 percent of all
frozen water on Earth
Rushing water is used to is in Antarctica, around
make power at giant the South Pole.

hydroelectric dams around the
world. As the water moves

through the dam, it turns turbine
machines that spin
so quickly they
create electricity.

120

Stone for grinding Grain grown in
wheat into flour Mesopotamia

Only 2.5 percent of the
Earth’s water is fresh. It
is found mostly in rivers,
lakes, and glaciers.

Land of the rivers

The first cities were built in
Mesopotamia (now mainly Iraq)
around the Tigris and Euphrates
rivers. The rivers allowed goods
and people to move around and

provided essential water
to drink, cook with, and use

to water crops.

Stone sickle
for cutting
crops

Kayaking

Water sports We lose water

Without water there from our bodies
would be fewer ways for us
to have fun. There would be through sweating
nothing to swim in or surf on,
and no kayaking or sailing. There when we are active
would be no snow for skiing or and play sports.
sledding and we could never

build a snowman.

Bad for
the environment

More than 200 billion plastic
water bottles are used around
the world each year. Making the
bottles releases lots of harmful
gases into the air, and only one

in five bottles is recycled—
the rest are thrown out
as garbage.

Plastic water bottles

121

Glaciers SEE ALSO
▸▸ Antarctica p.24
Glaciers are slow-moving rivers of ice. They form high up
in mountains or regions near Earth’s poles and flow ▸▸ Arctic p.25
downhill. The front of a glacier may melt to make a river or
lake. If a glacier reaches the coast, huge blocks of it break ▸▸ Changing world
off and float away into the ocean as icebergs. pp.50–51

▸▸ Climate change
p.60

▸▸ Erosion p.93

▸▸ Mountains p.172

How are glaciers made? The dark streaks A lake of melted ice Glaciers can wear
on the surface are often forms at the down the sides of
Glaciers are made from snow that builds rocks carried along front of a glacier. mountains, making
up and turns into ice. Eventually, there is by the glacier. them pyramid-shaped.
so much ice that it starts to flow downhill.

Signs of U-shaped valley Sharp ridge Giant rocks
glaciers Glaciers carve steep-sided valleys An arête is a sharp ridge of rock Glaciers can pick up giant rocks and
into flatter U-shaped ones as ice that separates two valleys that dump them far from where they
Some parts of the world and rock grind the hillside away. once had glaciers in them. came. They are called erratics.
were once colder and
covered in glaciers.
As the climate warmed,
the glaciers melted away.
However, they left signs
in the landscape that they
were once there.

122

Governments SEE ALSO
▸▸ Law p.145
A government is an official group of people that runs a ▸▸ Medicine p.160
▸▸ Trade p.257

country. Governments keep their people safe through ▸▸ School
rules called laws. They often try to keep the peace with pp.272–273
other countries, and can help provide services such as
schools and hospitals. Most governments try to help ▸▸ Work p.274

▸▸ World p.275

people lead better lives.

How a government works Head of state
One person is in charge of
Each country has its own system of government each country, such as a
that looks after its people. Large countries have president or queen. They
different levels of government, while smaller represent it when meeting
countries have simpler systems. with other countries.

Local governments National government
Local governments run The national government looks after
smaller areas within the whole country. It makes laws and
countries. They look after has people in charge of different
local issues, such as roads areas, such as education.
and libraries.
Electorate
People in many countries
choose their governments
by voting in elections.
They are the electorate.

Types of government Constitutions

Most countries in the world are democracies. A constitution is a written document
They elect (choose) who is in government. that sets out the aims and values
Other countries have heads of state of a country and how it should be
who aren’t chosen. ruled. The US constitution was
written in 1787.

Democracy Monarchy Dictatorship
In a democracy, people vote A monarchy is a family Dictators often rule by force.
for a government and a head system in which the job of
of state to rule them and take the head of state is passed They use an army to make
from the king or queen to people do what they say.
decisions for them. their child or relative.
123

Grasslands SEE ALSO
▸▸ Africa p.12
Grasslands are large areas covered in grass with just ▸▸ Animal homes
a few trees. They are dry, but get more rain than
deserts do. Grasslands are known as savannas in p.23
Africa, steppes in Russia, prairies in North America, ▸▸ Birds p.39
and pampas in South America. ▸▸ Deserts p.78
▸▸ Migration p.166
Grassland life Hoopoes make a ▸▸ Monkeys and
“hoopoe” sound
Many different animals live in grasslands. as they fly. apes p.170
Some feed on the grasses and walk long
distances to find enough grass to eat. Other Plains zebras live
animals hunt and eat these plant-eaters. together in herds, to
protect themselves
Acacia trees have White rhinos from hunting animals.
thorns around charge if they
their leaves. need to defend Nile crocodiles attack
themselves. animals that come to
drink at the water.
Giraffes can reach Female lions
the top of the trees hunt in groups. African rock pythons
to eat the leaves. squeeze to death the
Milkweed locusts animals they catch.
Meerkats take can be heard
turns looking chirping but are
out for animals not often seen.
that might
eat them. Insects called
termites build
Vervet monkeys large mounds
eat berries and together.
insects.

Mole rats stay South Africa
underground Kruger National Park in South
all their lives. Africa is home to many different
animals. The park sits in a huge
Aardvarks have long area of grassland. It is a protected
tongues to feed on area where park rangers try to
termites in their mounds. keep the animals living in it safe.

124

Gravity SEE ALSO
▸▸ Forces p.108
Gravity is an invisible force that pulls us back down ▸▸ Gases p.117
toward Earth when we jump in the air. If we throw a ▸▸ Measuring p.159
ball up it comes down because of gravity. Without it, ▸▸ Moon p.171
we would float off into space. ▸▸ Solar system

Falling to Earth p.233
▸▸ Sun p.247
Earth’s gravity pulls things
toward it. When a skydiver jumps
out of a plane, gravity starts to
pull him down. Eventually he will
use a parachute to slow his fall.

Air pushes up on the Gravity pulls the
skydiver as he falls. skydiver down
toward Earth.

Earth

The moon moves
around the Earth.

Isaac Newton Newton came up Moon
with the theory of
Scientist Isaac Newton gravity after Earth and moon
realized there was a pattern watching apples
behind objects falling fall from a tree. The strong pull of Earth’s gravity keeps
toward Earth. the moon moving around it. Without
125 gravity, the moon would disappear
into space.

Habitats SEE ALSO
▸▸ Coral reefs p.74
A habitat is the place a plant or animal lives. Habitats ▸▸ Deserts p.78
around the world have different temperatures and ▸▸ Forests p.109
landscapes. Animals and plants have certain features ▸▸ Grasslands p.124
that allow them to survive in their habitats. ▸▸ Polar habitats

Tundra Polar regions p.197
This cold habitat Very few plants ▸▸ Seashores p.220
has very few and animals
trees, plants can survive Coniferous
are small, and in the freezing forest
animals often temperatures This habitat is
move away of this icy habitat. full of coniferous
after the short trees, which
summer. keep their
needlelike leaves
all year round.

Tropical rain forests

cover 7 percent

of Earth, but are home

to more than half

the world’s plants
and animals.

Desert
Rocks and sand cover
this very dry habitat.
Animals and plants
have to be able to
survive with very
little water.

Rain forest Grassland Deciduous forest Ocean
Trees grow quickly in this Grasslands have more rain This habitat has four This saltwater habitat
warm, rainy habitat. They than deserts, but not enough seasons. The trees drop covers 70 percent of
provide food and homes for for many trees to grow. Most their leaves in autumn and Earth’s surface. Some
thousands of different animals. animals here eat grass. grow them again in spring. animals live deep down.

126

Hearing SEE ALSO
▸▸ Brain p.45
Hearing happens when our ears receive a sound. Sound is a
vibration that travels through the air and into our ears. The ▸▸ Communication
sound travels into the hidden parts of the ear and our brain p.69
identifies what we hear.
▸▸ Human body
p.130

▸▸ Music pp.176–177

▸▸ Radio p.203

▸▸ Sound p.235

The ears are The ear The smallest
shaped like cups bone in your ear
to catch sound. The ear is much bigger than it looks is the size of a
from the outside. The inner ear and
outer ear are hidden inside our heads. grain of rice.

Inside the ear

Outer ear 2. Ear drum 3. Bones 5. Nerve
The ear drum is Three tiny bones This nerve sends
a tiny disk with called the ossicles sounds to the brain
skin stretched pass the vibrations as electrical signals.
over it. It picks up along.
sound vibrations.

1. Ear canal Inner ear The curled
Sound vibrates Middle ear part of the
through the air inner ear is
and into the ear. 4. Inner ear called the
The inner ear cochlear.
Brilliant brain contains liquid-filled
tubes. The vibrations
The brain makes sense move through the
of the signals from the liquid and tiny hair
ear. For example, if cells in the cochlear
someone is talking to us, detect the sounds.
the brain works out what
the meaning of the 127
sounds are.

Heart SEE ALSO
▸▸ Body cells p.41
The heart is a pump about the size of a fist. It is mainly ▸▸ Brain p.45
made of muscle and it pushes blood around the body ▸▸ Feelings p.99
by squashing itself in and out around 80 times a minute. ▸▸ Human body
Blood is a liquid that carries oxygen and food around the
body. If the heart stops beating, the body stops working. p.130
▸▸ Lungs p.149
▸▸ Medicine p.160

Inside the heart This artery carries Circulation
blood without
The heart pumps blood oxygen to the lungs. Blood with oxygen in it travels
every second of the day. around the body, pumped along
The right side of the heart by the heart. The oxygen is
sends blood to the lungs. dropped off in different places,
The left side sends blood then comes back to the heart
to the rest of the body. to be pushed to the lungs.

Atrium Artery Vein
The heart has two Heart
“chambers” on each
side, called atriums.

Valve
Valves are gates that
only open one way, so
blood can only travel
in one direction.

Blood

Blood contains tiny parts
called cells. Red blood cells
carry oxygen and waste
gas. White blood cells kill
germs. Broken bits of cells
stick together to make a
scab when the body is cut.

Vein Artery
Blood arrives from Blood is pushed
the body through out to the body in
tubes called veins. tubes called arteries.

128 Blood vessels

Hibernation SEE ALSO
▸▸ Amphibians p.15
For many animals, finding enough food in winter is hard.
Some animals migrate, or move, to warmer areas. Others ▸▸ Animal groups
survive by going into a deep sleep, called hibernation. They p.22
wake up again in the springtime when there is more food.
▸▸ Day and night
p.77

▸▸ Mammals p.154

▸▸ Migration p.166

▸▸ Seasons p.221

Dormouse Bats hibernate
upside down
These small mammals make in caves
cosy nests under leaves on or trees.
the forest floor, or at the
bottom of hedges.

Bat

Bats enter a deep
hibernation. Their
heart rate drops
from 400 to 25
beats per minute.

The furry tail Dormice can
wraps around
the mouse’s face curl up and sleep
to keep it warm. for up to

Wood frog seven months

in a year.

Wood frog Do bears
hibernate?
This frog’s body freezes in
the winter and its heart Bears sleep in the winter,
stops beating. When the but not very deeply, so
weather gets warmer, its they can be woken easily.
heart starts beating again This is called a torpor. It is
and the frog thaws out. like hibernation, but
without such a deep sleep.

129

Human body SEE ALSO
▸▸ Biology p.38
The body is made from lots of different parts ▸▸ Body cells p.41
called organs. Each organ has a different job ▸▸ Carbon cycle p.49
to do. Organs work with muscles and other ▸▸ Heart p.128
parts of the body to make important things ▸▸ Lungs p.149
happen, such as breathing, digestion, ▸▸ Monkeys and
and movement.
apes p.170
Body systems Respiratory system
The lungs bring air into Nervous system
Organs that are linked the body and send waste The brain thinks
together are called systems. air out. They supply and controls body
Each system has its own job, oxygen to the blood. movement. Signals
but they work together, too. are sent to the brain
through nerves.
Body ingredients
Circulatory
The human body is made up of tiny parts called system
cells. The cells of the body contain lots of The heart pumps
different ingredients. They all have different blood around the
uses in the body. body in a loop to
transport oxygen
Calcium helps muscles One-fourth of our and food.

to work and the heart to bodies is carbon. It is Digestive
system
keep beating. also found in diamonds! The stomach and
intestines break
A tiny amount of iron Tears contain sodium Skin and hair down the food so
is found in the body. It chloride, which is the system it can be used to
makes your blood red. same as table salt. The skin is a power the body.
waterproof layer
that protects the Urinary system
body from germs The kidneys clean
and sunshine. Hair the blood and make
keeps us warm. urine from the
waste. The bladder
Skeletal system stores the urine.
The skeleton is a
frame of bones that Muscular system
protects the inner The muscles move
organs of the body. all the parts of the
It also allows body. They make the
movement. heart pump and
the lungs breathe.

Phosphorus helps Over half of the body
make bones strong. is made of water.
Matches burn using Water is found in our
phosphorus. blood and cells.

130

Imperial Japan A horned helmet SEE ALSO
was part of a ▸▸ Art p.28
During the Edo period, from 1603 to samurai’s armor.
1868, Japan was ruled by a series of ▸▸ Dance p.76
powerful men called shoguns.
Each ruled from the city of ▸▸ Knights p.142
Edo, which is now Tokyo.
▸▸ Musical
instruments
p.175

▸▸ Theater p.253

▸▸ War pp.278–279

Noble samurai Making music

Samurai were warriors who fought Music has always played
for a powerful lord and followed an important part in
strict rules. Their way of life was Japanese culture. This
called Bushido (bu-shi-do), “the instrument, called a
way of the warrior.” shamisen (sha-mee-sen),
is like a guitar. It provided
The main weapon was background music for
a sword called a katana. dance performances
and puppet theater.
Art
Shamisens have
Poets, painters, writers, and three strings
craftspeople made beautiful and a square
works of art during this time. body.
This print from 1857 shows a
traditional Japanese scene of Strict command
trees and a river in the snow.
Edo society’s chain of command
was strict. The emperor was the
leader, but the shogun was in
charge of the lords, who were
called daimyo. The daimyo were
in charge of the samurai army.

Emperor

Shogun (sho-gun)

Daimyo (die-myo)

Samurai (sa-moo-rai)

131

Incas SEE ALSO
▸▸ Aztecs p.35
The Inca people lived in the mountains along the west ▸▸ Crafts p.75
coast of South America. Between 1438 and 1532 ce, their ▸▸ Farming p.98
wealthy empire was the largest in the world. Society was ▸▸ Maya p.158
well organized and everyone knew their place. ▸▸ Gold pp.200–201
▸▸ South America

p.236

Inca society The ancient Inca city
of Machu Picchu
At the head of Inca society sits in the Andes
was an emperor called Sapa Mountains, in Peru.
Inca, meaning “Great Inca.”
Most people were peasant
farmers who worked for
the emperor and in
return were given
food and housing.

The Sapa Inca Sun god
was treated
like a god. He was This gold disk shows Inti,
carried in a chair the Inca god of the sun.
by servants. Every year the Incas held a
nine-day festival of eating,
drinking, and sacrifice to
honor the sun god.

Houses were Inca crafts
made of stone and
had thatched roofs. The Incas made sacred
objects from gold and silver
Everybody had to be used in temples.
to bow down to Craft workers also made
the Sabu Inca. fine pieces from clay,
leather, and feathers.

Farmers
planted
potatoes.

Llamas were Maize, or corn, was Gold llama
used for carrying an important food.
goods and for their wool.

132

Industrial Revolution SEE ALSO
▸▸ Buildings p.48
The Industrial Revolution was a time of huge growth in ▸▸ Engines p.92
industry brought about by the introduction of new ▸▸ Factories p.97
machinery. Factories were built to make products using ▸▸ Inventions
large numbers of machines. The revolution began in Britain
during the 1760s and later spread around the world. pp.136–137
▸▸ Machines p.150
▸▸ Pollution p.198

Factory work Steam trains Chimneys Steam engines
transported goods and belched out were used to
Factories contained rows of fuel, such as coal, to smoke all day. power ships.
machines that made things in large and from the factory.
amounts, such as textiles, iron and
brass goods, pottery, and glassware.
These machines were powered first
by water and then by steam.

Barges traveled on
canals carrying goods
between towns.

Workers lived Child labor
in small,
overcrowded Children as young as four
houses. worked in the factories
and mines. The work was
Small towns grew Horsedrawn carts often dangerous and Boys working in a cotton mill
up quickly around carried supplies to dirty. Children also swept in Georgia, 1900
the factories. the factory. chimneys and ran errands.
They worked up to 80
hours a week, but were
paid very little money.

133

Insects SEE ALSO
▸▸ Animal groups
Insects are the largest group of animals, and are found all
over the world. They have three pairs of legs and a tough p.22
outer covering, called an exoskeleton. Many insects have ▸▸ Eggs p.86
wings and can fly. ▸▸ Invertebrates

Butterflies Swallowtail Feelers called antennae p.139
butterfly help the butterfly ▸▸ Metamorphosis
A butterfly changes a lot in its to smell nectar and
life cycle. It starts as an egg, then stay balanced. p.163
hatches into a caterpillar. It wraps ▸▸ Migration p.166
into a chrysalis before hatching
again as a butterfly. Many insects have
wings, which let
them fly around.

There are Body parts
more than
Insects’ bodies are divided
900,000 into three parts: the head,
different types the thorax, and the abdomen.
of insects They have three pairs of legs
in the world. attached to the thorax and one
pair of antennae on
Red wood ant their heads.

Ants Thorax

Ants live together in groups called Patches of color on Head Abdomen
colonies, with thousands of the butterfly’s wing tell
workers and a queen. They other animals that it is
are small but strong—ants can not good to eat.
lift 20 times their body weight.
Desert locust Stag beetle
nymph
Beetles
Grasshoppers
Beetles are found on land and
These insects can leap in water all over the world. They
20 times their body length. have hard, shiny outer wings
They can also fly fast, that close over a soft inner set
reaching speeds of up of wings, to protect them.
to 8 mph (13 kph).

134

Inside Earth SEE ALSO
▸▸ Compass p.70
The Earth is made up of four layers. We live on its outer ▸▸ Earth p.83
▸▸ Earth’s surface
layer, or crust. The crust floats on a layer of extremely hot
p.84
rock called the mantle. Below this, our planet’s center, or ▸▸ Magnets p.151
▸▸ Metals p.162
core, is made of the metal iron. The upper mantle ▸▸ Volcanoes p.268
is made of hot,
partly liquid rock. In our planet’s
early history, it had
Earth’s layers
no crust and the
Like an onion, the Earth has layers.
Each layer is different. The deeper mantle was a sea of
the layer, the hotter it is, with the
inner core a scorching 10,800°F bubbling liquid
(6,000°C). rock.

The outer
core is made
of liquid iron.

The inner Earth’s crust
core is a ball is made of
of solid iron. solid rock.

The lower mantle is Magma
made of hot, solid rock. and lava

Magnetic Earth Main opening In some places on the
Earth’s surface, liquid rock
Because the Earth’s outer core is Magma bubbles up to the surface,
liquid, it moves as the Earth spins. chamber creating volcanoes. Liquid
This creates a magnetic field
around the Earth. This field keeps rock is called magma
out harmful energy waves from when it is inside the
space. It also lets us find directions Earth and lava on
when we use a compass.
the surface.
135
Lava flows

North South
Pole Pole

Magnetic field

The story of... Steam engine

Inventions The first steam engines
were used to pump water
Inventions are new ideas that solve problems out of mines. Later, engines
or prove useful to us. Thousands of years of were used to power
brilliant brainpower have resulted in things factories and trains. George
and ideas that have transformed people’s Stephenson’s Rocket train
lives. Even in the modern world, people keep was built in 1829.
coming up with new ideas and inventions.
Reaching 30 mph
Hard flint was Hand axe
broken down (48 kph), the Rocket was
to make sharp The hand axe was the first vehicle to
tools. the first stone tool in
prehistoric times. People dug travel faster than
for flint, which they shaped into a horse.
handcrafted axes to cut meat,
chop wood, scrape skins, and
protect themselves. Hand axes
were used for more than a
million years.

A rod, or axle, links the A tall chimney
wheels together— released
turning the axle uses steam from
much less energy than the engine.
turning the wheel.

Wheel The front
wheels were
The wheel was pushed around
invented more than by the engine.
5,000 years ago in Mesopotamia
(part of modern-day Iraq). Wooden 136
discs were attached to animal carts to
carry heavy loads. Later, wheels
became lighter, which made them

faster and smoother.

The Wright’s Flight
Flyer, built in
1903. In 1903, American brothers
Wilbur and Orville Wright built
a glider with a light engine.
Although Flyer took off for
only 12 seconds over 120 ft
(37 m), it was the first-ever
powered flight.

Plastics Antibiotics Antibiotic pills

Plastics are cheap to make, Infection-fighting
easy to shape, and last a long antibiotics battle bacteria inside
time. They can be hard, soft, or the body. They were discovered by
bendy. The first human-made accident in 1928, when Scottish
plastic was made by Belgium-born scientist Alexander Fleming noticed
chemist Leo Baekeland in 1905. bacteria dying around mold in his lab.
The bacteria-killing chemical
Now plastics are all around us. penicillin has since saved

many lives.

Thomas Edison (1847–1931) was an

American master of invention, patenting

1,093

ideas in his lifetime, including

batteries and light bulbs.

Computers

Computers are electric machines

that follow instructions. Modern

computers can do billions of

sums every second. We use

The first them to find, store, and share
electronic computer, information. The idea of a
computer was invented by
ENIAC, was huge, English engineer Charles
Babbage in the 1830s.
filling a room
measuring 50 ft

(15 m) long.

137

Internet SEE ALSO
▸▸ Codes pp.66—67
The Internet is a network that links together computers
all over the world. We use it to learn things, for ▸▸ Communication
entertainment, and to communicate with each other. p.69
The Internet was first thought of in 1962. Now, billions
of people use it every day. ▸▸ Computers p.71

▸▸ Satellites p.215

▸▸ Telephones
p.250

How the Internet works The cloud
Information kept somewhere remote
The Internet is made up of digital rather than on your computer is said
information stored on computers. to be “in the cloud.” This information
The information can be uploaded can be anything, such as facts, online
or downloaded through a network. games, news stories, or music.

Wi-Fi Satellite
Wireless Internet Satellites send
works using radio information
signals. between phones
and the Internet.
Smartphone
Smartphones are small,
handheld computers
that can connect
to the Internet.

Connection Website servers
Computers can connect to
the Internet using cables A website is a collection of linked pages.
that connect to Internet Each website has a unique Internet
service providers. address called a URL. Websites are
stored on computers called servers.
Internet service provider
Companies called Internet Web page
service providers have
massive computers. These
computers provide quick
access to the Internet.

Computer
A laptop or desktop computer
can store information and
access the Internet.

138

Invertebrates SEE ALSO
▸▸ Animal groups
Invertebrates are animals that don’t have backbones.
p.22
They are divided into many smaller groups, such as ▸▸ Animal homes

insects and mollusks. Ninety-eight percent of all p.23
▸▸ Habitats p.126
animals are invertebrates. ▸▸ Insects p.134
▸▸ Vertebrates
Antennae on the head
are used to “feel” p.266
movement in the air.
The hard shell
Insects Wings are protects the
attached to snail’s soft body.
Insects have a tough outer the body.
covering. They have six legs
and many can fly.

Praying mantis Front legs Snail
catch smaller
Worms can eat insects to eat. Mollusks
their own body
The body looks Mollusks have soft bodies with no
like a dead leaf, to weight in food skeleton and no legs. They live in
make the mantis in one day! water or wet soil.
hard for other
animals to see. Earthworm

Worms

Worms have long soft bodies with
no legs. Their bodies are split into
many parts, or segments.

Pincer claws

Venomous sting Hard outer
shell

Starfish

Scorpion Crab Suckers
underneath
Arachnids Crustaceans help the
starfish cling
These animals have eight legs, not six Crustaceans have hard outer shells, to rocks.
like insects. Arachnids include spiders, and more than eight legs. Most of
scorpions, and mites. them live in water. Echinoderms

139 These animals have bodies split into
equal parts around a disk in their
middle. They all live in the sea.

Iron Age SEE ALSO
▸▸ Bronze Age p.47
During the Iron Age, people began using iron ▸▸ Farming p.98
tools and weapons instead of bronze ones. ▸▸ Metals p.162
It started about 3,200 years ago and lasted ▸▸ Rocks and
for around 1,000 years, depending on the
area. Iron tools were stronger and more minerals p.214
durable than anything before. ▸▸ Trade p.257
▸▸ Vikings p.267

Tools Weapons

Iron tools allowed farmers and builders Iron weapons were lighter and
to work better. They were able to grow cheaper to make than weapons
more crops, clear land for farms, made from bronze. Well-made iron
and build bigger buildings. weapons were also stronger and sharper
than bronze ones. Having good weapons
meant societies could build powerful armies.

This iron sickle would Hill fort
have been attached to
a wooden handle and Hill forts are Iron Age
used to cut wheat. villages built on the
top of hills. They had
Iron cutting edge Danish iron earth or stone walls Iron Age hill fort in
sword from the around them. Hill forts Dorchester, UK
Making a sword was Viking period of allowed people to see
very difficult. The 800–1100 ce the enemy approaching
best swordmakers and prepare themselves
were well paid. for attack.

The walls at the base
of the fort acted as a
protective barrier.

Making iron 1. Dig it out 2. Heat it up 3. Pour it in
Iron is dug from the ground The iron ore is heated to high The melted iron is poured into
Making iron items is a in lumps, called iron ore. temperatures to make it melt. a shaped mold and left to cool.
process that needs great
skill and care. The iron
must be made extremely
hot before it can be shaped
into a weapon or a tool. How
we shape iron today is similar
to how Iron Age craftsmen
performed the task.

140

Jupiter SEE ALSO
▸▸ Astronomy p.32
Jupiter is the largest planet in the solar system, and ▸▸ Atmosphere p.33
the fifth planet from the sun. It is a “gas giant” made ▸▸ Elements p.90
of hydrogen and helium. Jupiter does not have a ▸▸ Gases p.117
solid surface like Earth. ▸▸ Solar system p.233
▸▸ Solids p.234
King of the planets ▸▸ Storms p.246

Jupiter is so large that 1,300
Earths could fit inside it. A
huge storm in its atmosphere,
called the Great Red Spot, is
more than twice the size
of Earth. Jupiter is the
third brightest object in
our night sky after the
moon and Venus.

Scientists have Io Europa Ganymede The striped bands and
been watching 141 swirls are shaped by
the Great Red strong winds.
Spot storm
since 1830. Callisto

Winds swirling
around the

Great Red Spot

reach speeds of more
than 250 mph
(400 kph).

The Galilean moons

Jupiter has more than 60 moons
of different sizes. Its four largest
moons are called Io, Europa,
Ganymede, and Callisto. They are
known as “the Galilean moons”
because they were discovered by
the Italian scientist Galileo Galilei
in the 17th century.

Knights The helmet SEE ALSO
was shaped ▸▸ Castles p.53
Knights were men who owned big pieces to help avoid ▸▸ Clothing pp.62–63
of land in Europe between the 600s and direct attack. ▸▸ Europe p.94
the 1600s, a time period known as the ▸▸ Flags p.102
Middle Ages. They trained from age ▸▸ Metals p.162
seven to be fighters and lead armies. ▸▸ Sports p.239
▸▸ War pp.278–279
Armor
Knights carried
Knights wore suits of armor to protect them their shield on
from enemy weapons, such as swords. The first a strap when
armor was made of mail, which is rings of metal not using it.
linked together. Later armor also included
sheets of shaped steel.

Curved armor
protected the
knight’s elbow.

Squires Steel gloves
were made of
Each knight had a squire to more than 40
assist him. Squires looked metal pieces.
after their knight’s armor,
sharpened his weapons, and A belt held the
cared for his horse. Some knight’s sword
squires later became knights. and dagger.

Knights wore Mail was heavy to Designs
colorful outfits wear, but offered
for jousting. good protection. Each knight had a special
design passed down to him
by his father. Knights put
their design on their shield
so others would recognize
them in battle. Men called
heralds recorded which
knight had which design.

Jousting

At jousts, crowds watched as knights on horseback
raced at each other holding blunt, wooden sticks
called lances. They scored points by hitting the
other knight or knocking him off his horse.

142

Lakes SEE ALSO
▸▸ Climate change
A lake is a large body of water surrounded by land.
Most lakes contain fresh water, but some are salty. p.60
Lakes are usually found in high areas or near large ▸▸ Factories p.97
rivers. The water in lakes comes from streams or ▸▸ Farming p.98
rivers around them. ▸▸ Water pp.120–121
▸▸ Rivers p.211
How we use lakes ▸▸ Water cycle

Lakes provide water for factories, farming, p.270
energy, sports, and homes. Nearly all lakes
are natural but some, known as Oxbow lakes
reservoirs, are made by people.
Rivers sometimes change their
Lakes form when course. When they do, bends in them
water fills hollows may become cut off to form U-shaped
in the landscape. bodies of water called oxbow lakes.

A deep bend,
or meander,
forms in the
course of
the river.

Lakes provide water for us The river
to drink, wash up, and bathe makes a
and shower. shortcut
and changes
its course.

Many lakes have an outlet, An oxbow
such as a river, from which lake forms
as the river’s
water leaves. new course
separates
from it.

Wet or dry?

Lakes can dry out if there is a long
period without rain, called a
drought, or if the climate changes.
They may reappear when the rain
returns or stay dry forever.

Lake water is used
for farming, making
goods, and producing

electricity.

143

Language SEE ALSO
▸▸ Ancient Rome
Language is how people communicate. Across the world,
people speak many different languages. There are more p.20
than 7,100 in total, some spoken by millions of people and ▸▸ Storytelling
others by just 100. These languages often sound very
different from one another, and can look different pp.42–43
when written down. ▸▸ Books p.44
▸▸ World p.275
The most-spoken languages nee-how ▸▸ Writing p.280

There are almost 7.5 billion people in the Hola Mandarin
world today. About one-third of them This is the most
speak one of five languages, which are spoken language
used by countries all over the world. in the world.
Forms of Mandarin
Hello Chinese are used
all over China.
marr-hah-bah

o-la

nuh-muh-stay

Arabic Hindi English Spanish
This is spoken This is one English is now This is spoken in
across North of the official spoken in every Spain and parts
Africa, the languages of continent and in of South and
Middle East, and India. It is also an many countries, Central America,
in many other official language including eastern Asia,
countries. in Fiji. the US. and Africa.

295 310 360 405 955

million million million million million

Sign languages Dead languages

People sometimes use hand shapes, body Some languages die out when
movements, and facial expressions to talk, their speakers start using
another language. Latin
rather than spoken language. This is called a was once spoken in the
sign language. It is useful if someone cannot Roman Empire, which
included much of
hear or speak. ”Yes” in American Europe. It’s now a
sign language dead language, but
”No” in American sign language can still be read
and written.

Latin words
from the
Roman Empire.

144

Law SEE ALSO
▸▸ Changing world
Laws are official rules for people to follow. The
government writes laws for the whole country. Some pp.50–51
laws stop people from doing bad things (crimes), such as ▸▸ Codes pp.66–67
stealing. These are called criminal laws. Other laws try to ▸▸ Governments
improve life, such as making sure people are paid a fair
amount of money for doing work. p.123
▸▸ Trade p.257
Law court Defendant ▸▸ Work p.274
The defendant is the ▸▸ World p.275
If someone doesn’t follow person who is said to have
the law, they can be punished. committed the crime. Judge
A criminal law court is where The judge controls the
it is decided if someone has Defense court, and may give the
committed a crime, and if Defense lawyers try to stop defendant a punishment,
they should be punished. the defendant from being such as imprisonment, if
This process is called a trial. punished by arguing for them. they did the crime.

Prosecution Witness
Prosecuting lawyers try A witness is
to make the judge and jury someone who
believe that the defendant knows something
did the crime. about the crime.
They tell the court
what they know.

In the UK, Public Jury
Ordinary people are A group of usually 12
it is against allowed into courts to see ordinary people hear
the law to what decisions are made. about the crime and
decide if the defendant
deliberately disturb did it.
someone by
Hammurabi’s laws
knocking on their
front door.

Police First laws

The police make sure people Police cars travel One of the earliest sets
follow laws. They capture people at high speeds to of laws was drawn up
who might have broken catch criminals. by King Hammurabi of
laws. This is called Babylon, who ruled
putting someone from 1792 to 1749 bce.
under arrest. There are 282 laws
about the family,
trade, and wages.

Police car

145

Life cycle SEE ALSO
▸▸ Body cells p.41
Like all animals, humans are born, grow up, and can have
children of their own. This is called a life cycle. There are ▸▸ Cells p.56
many different stages that a human goes through on their
journey from birth to adulthood. ▸▸ Genes p.119

▸▸ Human body
p.130

▸▸ Metamorphosis
p.166

▸▸ Skeleton p.228

Baby Toddler
Babies are very small and Toddlers learn how to walk,
can’t feed themselves or talk. talk, and feed themselves.
They need parents or carers They grow teeth called milk
to take care of them. teeth, which fall out and are
replaced with adult teeth.

Growing up Child
Children grow
Everyone starts life as just and learn quickly.
two cells. We grow into They are smaller
than adults and
children and eventually adults. still have a lot of
skills to learn.
Sperm and egg
A sperm cell joins Unborn baby
an egg cell inside
the mother’s womb. Babies grow inside the
After nine months, mother’s womb. Doctors look
the cells have grown at the growing baby using a
into a baby. process called an ultrasound.
At 12 weeks a baby is about
The the size of a lime.

oldest person Teenager
Chemical signals called
recorded died at 122 hormones tell the body to
years and 164 start changing from a child
days old. into an adult.

Adult 146
Adults can make their own
children. Males produce
sperm cells and females
produce egg cells.

Light SEE ALSO
▸▸ Color pp.26–27
Light is a type of energy that bounces off objects and into ▸▸ Energy pp.88–89
our eyes—we need it to see things. Light can change into ▸▸ Invertebrates
other types of energy such as heat or electricity. Dark is
the absence of light. p.139
▸▸ Materials p.157
▸▸ Sight p.226
▸▸ Sun p.247

White light The light bends Light sources
as it hits the
White light is actually made from all prism. This is The main source of light
the colors of the rainbow. We can called refracting. on Earth is the sun.
split white light into colors by Artificial light sources
shining it through a prism. White light is split include light bulbs,
into seven colors. candles, and oil lamps.
Light travels in Some animals, such as
straight lines. jellyfish and fireflies,
produce their own light.

The sun is a natural
light source.

Shadows Reflection A candle is an artificial
light source.
A shadow is a dark area where light More light bounces off shiny
is blocked by an object. It takes the surfaces like mirrors or still water. Some jellyfish can
shape of the object blocking the light. This is called a reflection. glow in the dark.

147

Liquids SEE ALSO
▸▸ Atoms p.34
Liquids are runny materials. They can be poured into
things, and move to fit the shape of their container. ▸▸ Changing states
Liquids make a pool, not a pile. We drink liquids including p.57
water. When a liquid cools, it can become a solid.
Heating a liquid can create a gas. ▸▸ Gases p.117

▸▸ Rivers p.211

▸▸ Solids p.234

▸▸ Water cycle
p.270

What liquids do Around

The things a liquid can do are called 75 percent
its properties. For example, liquids
can be heated to cook things. of your brain
Liquids are good at mixing because is made of
of the way they flow and move.
Some liquids flow more easily water.
than others, but they all
change shape to fit Dissolving
their containers.
Some materials dissolve (disappear into)
Liquids can liquids. If we add salt to water, it becomes
be poured. salty water. We can’t see the grains of salt
because they have dissolved into the water
to make salt water.

Water

Salt Salt water

Liquids move Water
to fit the
shape of their Two-thirds of the Earth’s surface is covered
container. in water. Water is essential because living
things need water to survive. Animals drink
water and plants take water in
from the ground or air.
Most living things are
made up of at least
half water.

Liquid particles
Liquids are made from tiny particles that
move around quickly and stick together in
groups. When they cool, they slow down
to eventually become solid.

148