Oasis Science and Technology 4

Rosebush Jasmine Marigold

fig: shrubs

Some special characteristics of the shrubs are listed below:
i. These are bushy plants.
ii. They usually live for more than one years.
iii. Their stem is woody and strong.
iv. They have woody branches.

Resonable facts
Why does rose belong to the shrub category?

The rose belongs to the shrub because it is a bushy
medium-sized plant.

Trees

Trees are tall and big plants. They have a very strong woody stem.
The tall and big plant with a woody stem is called a tree. Peepal trees,
banyan trees, sal etc. are trees.

banyan sal salla

fig: trees

Some special characteristics of the trees are listed below:
i. They are tall and strong plants.

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ii. They live for many years. They are perennial plants.
iii. They have a huge, woody stem.
iv. They have woody branches.
Plants can also be divided into aquatic plants and terrestrial plants.

Fact file
The amazon rainforest produces half the world’s oxygen
supply.

Aquatic plants

There are different kinds of plants growing in water. These plants are
a source of food for aquatic animals. The aquatic plant may be floating
on the water or completely inside the water. The plants that complete
their lifecycle in water are called aquatic plants. Lotus, waterlily and
hydrilla are some water plants.

lotus waterlily hydrilla

fig: aquatic plants

Some special characteristics of aquatic plants are listed below:
i. They have weak and undeveloped roots.
ii. They have air sacs in roots and stems.
iii. Their roots and stems are flexible.
iv. Their roots and stems are covered with wax.

Activity
Ask your guardians to find a water plant for you. Do
not go looking for it alone because you may drown.
Observe the water plant and mention some of its
characteristics.

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Terrestrial plants

The cactus grows in the desert. Pine trees grow in cold and dry
mountains. We grow crops and vegetables on land. The plants that
complete their lifecycle on land are called terrestrial plants. Radish,
paddy, sugarcane and potato plants are some terrestrial plants.

paddy sugarcane potato
fig: terrestrial plants

Some special characteristics of terrestrial plants are listed below:
i. They have strong and developed roots.
ii. Creepers, climbers and herbs have weak stems.
iii. Most of them have developed stems.

Fact file
Apple, onion and mango have the taste. Close your nose
while eating them to notice the taste.

Resonable facts
Why do land plants have developed roots?

The land plans have developed roots because they
need to go far to search for water.

Parts of the flowering plant

A flowering plant has two parts: root system and shoot system.
Root system
Roots grow under the soil. They help the plant to absorb water and
minerals. The underground part of the plant is called the root system.
It fixes plants into the soil.

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Shoot system

A shoot system is the part of the plant
that grows above the soil. It contains
a stem, branches, leaves, fruits and
flowers. The stem is a strong woody
part of the plant. Branches grow from
the stem. Leaves are green. They
make food for the plant. The colourful
part of the shoot system is called a
flower. The flower produces fruit and
seeds.

flowering plant

Activity
Uproot a potato plant and observe its parts.
Draw the diagram and label it.

Summary

1. The plant kingdom includes those organisms which have green
leaves.

2. The plants that do not bear flowers and seeds are called non-
flowering plants.

3. The plants that bear flowers and produce seeds are called
flowering plants.

4. The small plants with weak fleshy stems are herbs.

5. The medium-sized plants with woody stems are called shrubs.

6. The tall and big plants, with woody stems, are called trees.

7. The plants that complete their lifecycle in water are called aquatic
plants.

8. The plants that complete their lifecycle on land are called terrestrial
plants.

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9. The underground part of the plant is called the root system.
10. The colourful part of the shoot system is called a flower.

Model Questions with Their Answer

1. What is a root system?
The underground part of the plant is called a root system.

2. Why does tomato belong to the flowering plant?

Tomato belongs to the flowering plant because it bears flowers
and seeds.

3. Differentiate between herbs and trees.

The differences between herbs and trees are:

SN Herbs SN Trees

1 The small plants with 1 The tall and big plants

weak fleshy stems are with woody stems are

herbs. trees.

2 They live for few months. 2 They live for many years.

4. Write any three characteristics of trees.

Some special characteristics of trees are listed below:
i. They are tall and strong plants.
ii. They live for many years. They are perennial plants.
iii. They have woody stems and branches.

5. Observe the given diagram and answer the fololwing?
i. What type of plant is it?
It is a climber plant.
ii. Why does it climb the support?
It climbs the support to collect sunlight.

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Exercise

1. Fill in the blanks with an appropriate word.

tree medium non-flowering plants herbs

a. Presence of chlorophyll makes ………… green.

b. Flowers and seeds are absent in ………… plants.

c. The plants that grow in particular season only are …………..

d. Shrubs are ……. sized plants.

e. The tall and big plants with woody stems are …….

2. Write true for the correct and false for the incorrect statement.
a. The organisms that contain chlorophyll are called plants.
b. Grasses, wheat, tomatoes etc. are shrubs.
c. Rosebush, jasmine and marigold etc. are trees.
d. The aquatic plant may be floating on the water or completely
under the water.
e. Cactus grows in the desert.

3. Choose the best answer from the given alternatives.
a. Which of the following is a non-flowering plant?

Pinus Pine Mushroom Potato

b. Which one of the following is a herb?

Pine Mushroom Pinus Potato

c. Which one of the following is an aquatic plant?

Lotus Pine Mushroom Potato

d. Which one of the following is a perennial plant?

Pine Lotus Mushroom Potato

e. Which one of them is a land plant?

Hydrilla Marigold Lotus All of them

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4. Match the following.
Mushroom desert plant
Rose water plant
Hydrilla herb
Cactus spore
Seasonal plant shrub
5. Answer the following questions in a word each.
a. Which type of plant has a weak and fleshy stem?
b. What are tall and strong plants called?
c. Give an example of an annual plant.
d. Which part of the plant produces fruit?
e. What is the underground part of the plant called?
6. Write any two differences between:
a. Land plant and water plant
b. Herbs and shrubs
c. Flowering plant and non-flowering plant
7. Give reason.
a. The stem of the aquatic plant is covered with wax.
b. Terrestrial plants have developed roots than aquatic plants.
c. Cucumber plants have tendrils.
8. Study the given diagram and answer the following questions.
i. Is it an aquatic plant or a terrestrial plant?
ii. Why does it have long roots?
9. Answer the following questions.
a. Write some characteristics of plants.
b. Write any three main characteristics of herbs.
c. List any three special features of shrubs.
d. What is a tree? Write any two of its main characteristics.
e. Mention the characteristics of aquatic plants.
f. Write a short note on the shoot system.
10. Project work.

Observe the mustard plant. Make a list of the parts you see in it.

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5UNIT Life Process

Introduction to life process

A cow is a living thing. It can breathe and eat. It can walk, hear and
give birth to babies. Similarly, a mango plant is also a living thing. It
breathes, grows and produces seeds. Growth, sense, eating, walking,
breathing and giving birth are common among living things. These
activities keep them alive. The activities that a living thing does to
continue living is called the life process.

respiration in fish Growth in plants photosynthesis

Movement grazing for nutrition reproduction: lion and its cubs

Every living thing is born. They grow into an adult. They produce
babies. They grow old and die. This process is called the lifecycle. The
process in which a young one is born, grows into an adult, reproduces,
grows old and dies is called the lifecycle.

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lifecycle of human beings

Fact file
Every life starts from a single cell.

Activity
What are the characteristics of living things? Make a list.

1. Nutrition
2.
3.
4.
5.

Resonable facts
Why is a cell called the building block of life?
The cell is called the building block of life because
every living thing is made up of cells.

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Unit Animal life
5.1

Key terms and terminologies

1. Life process: The activities that a living thing do to continue life
on the earth is called the life process.

2. Lifecycle: The process in which a young one is born, grows into
an adult, reproduces, grows old and dies is called the lifecycle.

3. Kid of goat: A baby goat is called a kid.
4. Tadpole: The larva of the frog is called a tadpole.
5. Larva of butterfly: A larva of a butterfly is a long insect that is

hatched from eggs.
6. Pupa of butterfly: The pupa of the butterfly is an insect that lives

inside the cocoon.

Introduction

Animals are born from their parents. Oviparous animals lay eggs that
hatch into young ones. Viviparous animals give direct birth. Young
ones will grow into adults. They produce new offspring. New
offspring grow old and die. Every living thing gives birth to babies.
In this way, lifecycle of an animal continues.

hen and chicks cat and kitten dog and puppies tiger and cubs

fig: animals and their offspring

Activity
Search information on the lifecycle of a honey bee.

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Fact file
Our bodies change and develop throughout our lifetime.

The lifecycle of a goat

A goat is a vertebrate mammal. There are three stages in the lifecycle
of a goat. They are birth, childhood and adulthood. A baby goat is
called a kid. The kid grows into an adult goat. It gives birth to young
ones, grows old and dies.

The lifecycle of a hen

The hen is an oviparous animal. There are three stages in the lifecycle
of a hen. They are eggs, chicks and adults. When an egg is hatched, a
new chick comes out. It will grow into an adult hen. It will then lay
eggs. It covers them for three weeks until new chicks are hatched
from the eggs. Then it grows old and dies. This is the lifecycle of a
hen.

lifecycle of hen

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Resonable facts
Why does a hen lay eggs?
The hen lays eggs to hatch chicken and continue life.

Fact file
All lifecycles start from birth and end with death.

The lifecycle of a frog

A frog is an oviparous animal. It lives on land as well as in water.
There are four stages in the lifecycle of a frog. They are eggs, larvae,
young frogs and adult frogs.

Eggs

Eggs are laid in water. They will hatch into larvae.

Larva Eggs of frog
tadpole
Larva of the frog is called a tadpole. It looks like
fish. It has gills to breathe. It swims with the help young frog
of fins. A tadpole then changes into a young frog.
Young frog

A young frog grows legs. It then starts breathing
by its lungs. It changes into an adult frog in the
next stage.
Adult frog

An adult frog lays eggs in water.

Thus, the lifecycle of a frog continues.

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lifecycle of the frog

Activity
Make a model of the lifecycle of a frog on chart paper
and stick it in your class.

The lifecycle of the butterfly

A butterfly does not have a backbone. It is an invertebrate animal.
There are four stages in the lifecycle of a butterfly. They are eggs,
larvae, pupas and adult.

Fact file
Butterflies stick their eggs to the leaves of a plant.

Resonable facts
Why do butterflies lay eggs on leaves?
Butterflies lay eggs on the leaves of a plant because the
larvae when hatched need to eat the leaves.

Eggs

Butterflies reproduce by laying eggs. They lay eggs eggs of butterfly
on a leaf. Eggs are round and small. They will then
hatch into larvae.

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Larva

A larva is long insect hatched from an egg. It can larva of butterfly
move from one place to another in search of food. It
can eat a lot of leaves. It grows very fast. After a few
weeks it stops eating and changes into a pupa.

Pupa

The pupa lives inside a cocoon. It does not move from pupa of butterfly
place to place. It does not eat. It will change into a
butterfly and breaks the cocoon to come out.

Adult

An adult butterfly has six legs and four wings. butterfly
They can fly. They feed upon the nectar of the
flower. They lay eggs.

Thus, the lifecycle of the butterfly continues.

lifecycle of the butterfly

Activity
Make a model of the lifecycle of the butterfly on chart
paper and stick it somewhere in class for all to see.

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Summary

1. The activities that a living thing do to continue life on the earth is
called the life process.

2. The process in which a young one is born, grows into an adult,
reproduces, grows old and dies is called the lifecycle.

3. Oviparous animals lay eggs that hatch into young ones.
4. There are four stages in the lifecycle of a frog. These are eggs,

larvae, young frogs and adult frogs.
5. Larva of the frog is called a tadpole.
6. There are four stages in the lifecycle of the butterfly. These are

eggs, larvae, pupae and adults.
7. A larva moves from one place to another in search of food.
8. An adult butterfly has six legs and four wings.

Model Questions with Their Answer

1. Define the life process.
The activities that a living thing do to continue life on the earth is

called the life process.
2. What is the larva of frog called?
The larva of the frog is called a tadpole.
3. Why can frogs live on land as well as in water?
Frogs can live on land as well as in water because frogs use their

lungs to breathe on land and use their skin to breathe underwater.
4. Larva of the butterfly eats a lot. Give reason.
The larva of the butterfly eats a lot to collect enough protein to

change into pupa.
5. Have you seen transparent liquid inside the egg? Write its use.
Hen is an oviparous animal. Their chicken grows inside the egg.

Chick needs nutrition. So an egg of a hen is filled with transparent
liquid in it which is nutritious protein.

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Exercise

1. Fill in the blanks with an appropriate word.

tadpole oviparous lifecycle calf puppies

a. A cow will give birth to ………….

b. The process in which a young one is born, grows into an
adult, reproduces, grows old and dies is called ……….

c. Dog produces ………….

d. The hen is an ………… animal.

e. Larva of the frog is called…………..

2. Write true for the correct and false for the incorrect statement.
a. A tadpole changes into a young frog.
b. An adult butterfly has six legs and four wings.
c. The larva does not eat.
d. A baby goat is called a calf.
e. The frog has gills to breathe.

3. Choose the best answer from the given alternatives.
a. What is the baby of a goat called?

Baby Kid Chicken Calf
Cocoon
b. What is the larva of a frog called?

Tadpole Kid Caterpillar

c. Where do frogs lay eggs?

Water Leaf Holes Sand
Sand
d. Where does the butterfly lay its eggs?

Water Leaf Holes

e. Where does the pupa stay?

Tadpole Kid Caterpillar Cocoon

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4. Match the following.
Chicken nectar
Tadpole larva
Caterpillar does not eat
Pupa frog
Butterfly hen
5. Answer the following questions in a word each.

a. What is the process in which a young one is born, grows into
an adult, reproduces, grows old and dies called?

b. What is a baby of a hen called?
c. What does a butterfly reproduce through?
d. Where do the butterflies lay their eggs?
e. What does a caterpillar eat?
6. Write any two differences between:
a. Larva of frog and larva of a butterfly
b. Larva and pupa of a butterfly
7. Give reason.
a. Living things reproduce. b. A hen cover its eggs.
8. Rearrange pictures of stages of the lifecycle of a butterfly.

(a) (b) (c) (d)

9. Answer the following questions.

a. What is the life process?

b. Define lifecycle.

c. Describe the lifecycle of a frog.

d. Describe the lifecycle of a butterfly.

10. Project work.

What are the different stages in the lifecycle of a human being?

Discuss with your friends.

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Unit Plant Life
5.2

Key terms and terminologies

1. Nonflowering plant: The plants that do not have flowers and seeds are
called nonflowering plants.

2. Flowering plants: The plants that bear flowers and seeds are called flowering
plants.

3. Germination: The process in which a seed changes into a seedling is called
germination.

4. Seedling: The new plant produced by germination is called seedling.
5. Radical: Radical is a part of the seed that changes into the root system.
6. Plumule: The plumule is a part of the seed that change into the shoot system.
7. Mustard green: Mustard green is a leafy vegetable grown for vegetables.
8. Herbarium: Herbarium is a systematically arranged collection of dried

plants.

Introduction

Similar to the animals, plants also have distinct lifecycles. New plants
grow from seeds or spores. They grow into adult plants. They will
produce spores or seeds. They grow old and die. This way, the plant
life continues.

a non-flowering plant reproduces a flowering plant reproduces through
through spore seeds

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Lifecycle of a non-flowering plant

A mushroom is a non-flowering

plant. Spore, mycelium, fruiting

body and mushroom are stages

of the lifecycle of a mushroom.

When the spore gets air and

water, it will change into

mycelium. Mycelium produces

a fruiting body. The fruiting

body changes into the

mushroom. Mushroom

produces spores. In this way,

the lifecycle of a mushroom

continues. lifecycle of a mushroom

Activity
Find a mushroom and observe its parts.

Fact file
Banana contains a natural chemical that makes people feel
happy.

Resonable facts
Why does mushroom produce spores?
The mushroom produces spores because the spores are
the first stage of its lifecycle. They produce new mushroom.

The lifecycle of a flowering plant

A flowering plant reproduces from the seeds. Germination of seeds,
pollination, fertilization and dispersal of seeds are the different stages

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of the lifecycle of the flowering plant. Seeds get air, water and heat

from the environment and change into seedlings. The process in

which a seed changes into a

seedling is called germination. A

seed has cotyledons. They protect

the baby plant inside them. The

baby plant has radical and

plumule. During germination

radical changes into the root

system and plumule changes

into shoot system. germination of seed

A seedling will grow into an adult plant and bear flowers. Pollination
will occur. Fertilization produces a baby plant. The baby plant sleeps
inside the seed. Ovary of flower changes into fruit and contains seeds.
Seeds are carried away by animals, wind and rain to another place.
These seeds will germinate into new plants.

Fig. Pollination

Hence the lifecycle of the flowering plants continues.

Activity
Put topsoil in a plastic cup. Sow a maize seed in the
cup. Water it and wait for a few days. What will
happen? What is the process called?

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Resonable facts
Why should we water the seed after sowing it in the
soil?
We should water the seed after sowing it in the soil
because it needs water for germination.

The lifecycle of the maize plant

Maize is a flowering plant. A new maize plant germinates from the
seed. It will grow into an adult plant and bear flowers. Wind and
insects help in pollination. Fertilization occurs and seeds are formed.
These seeds can germinate into seedlings. The maize plant grows old
and dies. Hence the lifecycle of a maize plant continues.

Fact file
The male part of the flower is called the stamen. The
female part of the flower is called the carpel.

lifecycle of the maize plant

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The lifecycle of mustard plant

Mustard plant is a leafy vegetable. It is a flowering plant. A new plant
comes from the seeds. When the seeds absorb water, air and heat,
they germinate into seedlings. Each seedling can now grow into an
adult plant. The adult plant produces round, small, black seeds. These
seeds can germinate into new plants. They will grow old and die.
Hence the lifecycle of the mustard plant continues.

lifecycle of mustard plant

Vegetative Propagation

Banana is a flowering plant. It has delicious fruits. We have not seen
a seed in the banana. It is because they do not have a good quality of
the seed. Similarly, sugarcane, potato, rose, sweet potato and begonia
plants also do not have good quality seeds. They do not reproduce
from seeds. They usually grow new plants from other parts of the
body.

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banana rose sugarcane begonia
few plants that can grow from their vegetative parts

A new potato plant grows from a tuber. Sugarcane and rose grow
new plants from the stem. New begonia plants grow from the leaf.
New sweet potato grows from roots.

The lifecycle of the potato plant

The potato plant is a herb. It completes its lifecycle within a few

months. A new potato plant grows from the tuber. The plant will

become adult and bear flowers. Flowers change into fruits. Fruits

contain seeds. But these

seeds are not viable.

They cannot germinate

into healthy seedlings. It

takes a very long time.

Potato plants have lots

of tubers under the

ground. We eat those

tubers. Buds will grow

in these tubers and new

plants grow from them.

These tubers are now

planted in the soil. Hence

the lifecycle of the potato

plant continues. lifecycle of a potato plant

The lifecycle of one plant

is different from another. Herbs usually complete their lifecycle

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within one particular season. Shrubs complete their lifecycle within
few years. Trees have a very long lifecycle. They live for many years.
They are also called perennial plants.

Fact file
Potato is 80% water.

Activity
Break a branch of the rose plant. Put it in soil and water it
every day. Will it die or grow into a new plant? Experiment.

Resonable facts
Why is potato seed not used to grow new plants?
The potato seed is not used to grow new plants because
it does not grow good seedlings. It needs a very long
time.

Seasonal plant

Herbs are seasonal plants. They complete their lifecycle within a
single season. Cauliflower, radish, paddy and wheat are some
examples of herbs. When we plant them, they germinate into seedlings.
These seedlings grow into plants, plants bear fruits and seeds. Then
within a few months they die. They are also called annual plants.

Cauliflower radish paddy wheat

Perennial plants

Shrubs and trees are called perennial plants. They complete their

lifecycle usually more than two years. For example uttis, chilaune,

kahyer, sal, dhupi, etc.

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Sal chilaune kahyer peepal

Preparation of a herbarium

The herbarium is a systematically arranged collection of dried plants.
It helps in study and research. We can make a
herbarium ourselves.

Let's practise making a herbarium.
i. We should collect plants. The smaller the better.

ii. We should keep them inside the pile of old Herbarium
newspapers or a book.

iii. They should be pressed for a week.
iv. Then we can take them out.

v. We have to paste them into a chart paper.

Activity
Make a herbarium and present it in class.

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Summary

1. Non-flowering plants reproduce by spores.

2. Flowering plants reproduce by seeds.

3. Seeds, germination, pollination, fertilization and dispersal of
seed are the stages of the lifecycle of the flowering plant.

4. The process in which a seed changes into a seedling is called
germination.

5. During germination radical changes into the root system and
plumule changes into the shoot system.

6. The baby plant sleeps inside the seed.
7. New potato plants grow from the tubers.
8. The herbarium is a systematically arranged collection of dried

plants.
9. Herbs usually complete their lifecycle within one particular

season.
10. Shrubs complete their lifecycle within two years.
11. Trees have a very long lifecycle.

Model Questions with Their Answer

1. What changes into mycelium?
The spore changes into the mycelium.

2. What factors help in the dispersal of the seed?
Air, water and insect help in the dispersal of the seed.

3. Why is a baby plant found inside the seed?

The baby plant is found inside the seed because the seed protects
the baby plant and gives food.

4. Why is potato tubers planted in fields instead of seeds?

The potato tubers is planted in fields instead of seeds because
potato seeds cannot produce healthy seedlings but tubers can.

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5. Does every plant reproduce through spores and seeds? Research
on the topic and make a report.

Usually, non-flowering plants reproduce from spores and
flowering plants reproduce from seeds. However, some plants
reproduce from other parts of the body. A new potato plant grows
from a tuber. Sugarcane and rose grow new plants from the stem.
New begonia plants grow from the leaf. New sweet potato grows
from roots.

Exercise

1. Fill in the blanks with an appropriate word.

herbarium fruit mushroom seed seedling

a. A ………… is a non-flowering plant.

b. A flowering plant reproduces by the …………..

c. Process in which seed changes into ………. is called
germination.

d. Ovary of flower changes into ………… and contains seeds.

e. Systematicallyarrangedcollectionofdriedplantsis…………..

2. Write true for the correct and false for the incorrect statement.
a. The cotyledons protect the baby plant inside the seed.
b. The seeds will germinate into flowers.
c. A new potato plant grows from a tuber.
d. Trees complete their lifecycle within one particular season.
e. A new potato plant grows from the tuber.

3. Choose the best answer from the given alternatives.
a. Which one is a non-flowering plant?

Banana Banyan Mushroom Potato

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b. What does a flower produce?

Fruit Root Shoot Leaf

c. What helps in pollination?

Wind Sunlight Heat Soil

d. Which one reproduces through seeds?

Banana Potato Tomato Rose

e. How long does it take for a potato plant to complete its
lifecycle?

One season Two years Three years Many years
4. Match the following.
Spore herbarium
Maize tuber
Potato stem
Rose non-flowering plant
Dried stored plant seeds
5. Answer the following questions in a word each.
a. Give an example of a non-flowering plant.

b. Give an example of a flowering plant that does not reproduce
through seeds.

c. What process produces baby plants?
d. What process produces seedlings?
e. What part of the mustard plant do we eat?
6. Write any two differences between:
a. The lifecycles of a flowering plant and a non-flowering plant

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7. Give reason.
a. A cotyledon of seed stores food.

b. Farmers use rose stem to grow new
plants instead of seeds.

8. Study the given diagram and answer the
following questions.
i. What is growing from the potato tuber?
ii. Why is it growing from tuber instead of seed?

9. Answer the following questions.
a. How does a non-flowering plant reproduce?

b. What is germination?
c. What are the required conditions in which a seed germinates?
d. Describe the lifecycle of a flowering plant with an example.
e. How does the potato plant reproduce? Explain.
f. What is a herbarium?

10. Project work.

Do all plants have the same type of lifecycle? Do all plants
complete their lifecycle in the same duration? Discuss in a group.

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6UNIT Matter

Introduction

Our school bag is heavy. It contains books, copies, a lunch box and a
pencil. These things have mass and volume. The substances which
have mass and volume are called matter. The matter is made up of
molecules. There are three states of the matter. These are solid, liquid
and gas.

natural things man-made things

Solid state of matter

The matter in which molecules are very close to each other is called
solid. Solid is hard and strong. It has a fixed shape, size and volume.

book brick ice solid molecules

Gas state of matter fig: solids

The matter in which molecules are very far from each other is called
gas. It does not have a fixed shape, size and volume.

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water vapour gas molecules

fig: gases

The matter in which molecules are packed more loosely than in solid
but closer than in gas is called liquid. Its molecules can flow. It does
not have a fixed shape and size. It has a fixed volume.

water oil milk liquid molecules
fig: liquids

Fact file
The matter is made up of atoms and molecules.

Activity
Make a list of ten different things from your surroundings.
Classify them as solid, liquid and gas.

Solid Liquid Gas

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Unit Water
6.1

Key terms and terminologies:

1. Matter: The substances which have mass and occupy volume are called
matter.

2. Solid: The matter in which molecules are very close to each other is called
solid.

3. Gas: The matter in which molecules are very far from each other is called
gas.

4. Liquid: The matter in which molecules are packed loosely than the solid but
closely than the gas is called liquid.

5. Evaporation: The process in which liquid changes into vapour on heating is
called evaporation.

6. Condensation: The process in which vapour changes into liquid on cooling
is called condensation.

7. Freezing: The process in which liquid changes into solid on cooling is called
freezing.

8. Melting: The process in which solid changes into liquid on heating is called
melting.

9. Source of water: The place that gives water is called the source of water.

Introduction

Water is a matter because it has mass and occupies volume. Snow,
ice, frost, dew, vapour, liquid water etc. are various forms of water.
Water exists in all three forms of matter.

States of water

Water occurs in three different forms. They are called states of water.
They are:

i. Liquid form of water

The liquid form of water is present in lakes, ponds, rivers and
oceans.

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lake pond river ocean

ii. Solid form of water:

Snow on the top of mountains, ice at the poles of the earth and
hailstones are solid forms of water.

antarctica is covered with ice hailstones

iii. Gaseous form of water vapour from boiling
Vapour is the gaseous form of water. water


Fact file
Water is made of up hydrogen and oxygen.

Water can change its state.

If water is heated it will change into
vapour. The process in which liquid
changes into vapour on heating is
called evaporation.

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If vapour is cooled, it will change into water. The process in which
vapour changes into liquid on cooling is called condensation.

If water is cooled it will change into ice. The process in which liquid
changes into solid on cooling is called freezing.

If ice is heated it will melt into water. The process in which solid
changes into liquid on heating is called melting.

Fact file
Nearly 97% of the world’s water is salty and undrinkable.

Activity

Get some ice cubes. Heat them up. Continue heating until
they change into vapour. Put a block of ice-filled glass in
the path of the vapour. You will see water droplets around
the glass. Collect the droplets and put the liquid in the
refrigerator until it changes back into ice.

Properties of water

The properties of water are listed below: water takes shape of the container
i. Water is colourless, odourless and and maintains its level as well

tasteless.
ii. It can exist in all three forms of

matter.
iii. It has a fixed volume.
iv. It does not have a fixed shape.
v. It flows from higher to lower ground

to maintain a level.

Resonable facts
Why is water called a universal solvent?
Water is called a universal solvent because it dissolves
lots of substances.

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Sources of water

More than 70% of the earth’s surface is covered with water. It is
available in various forms. It is available in many places. The ocean
contains the largest amount of water. It has salty water. Rivers, ponds,
and lakes also have water. The place that gives water is called the
source of water. The source of water may be the underground or
surface source of water. Melting snow, springs, glacial lakes are the
sources of water in the mountainous region. Lakes, ponds, rivers and
springs are sources of water in the hills and plains. Underground
water can be collected by digging wells and from springs.

brook glacier aquifer
Fig: underground source of water
Fig: surface source of water

Fact file
Water maintains the temperature of the earth.

Uses of water

Water is very important for living organisms animals drink water from
and the environment. Some natural uses of pond
water are listed below:

i. Water keeps the surroundings cool.

ii. Plants absorb water for photosynthesis.

iii. Animals drink water from ponds and
rivers directly.

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iv. Rainfall is good for plants and crops.
v. Millions of animals live in water.

Water is very useful for us. We use water in

many ways.

i. We must drink enough water every day.

ii. Water is used to make food and drinks. some animals live in water
iii. We need water to

wash our clothes and

clean our house.

iv. We need water to bath

and brush.

v. We need water for drinking water water for irrigation

agriculture.

vi. It helps us to produce electricity and run water mills.

Activity
Observe the different activities that use water in your house.

Conservation of water resources

Water is very useful for us, animals, plants and the environment. Due
to overpopulation and deforestation water resources are drying up.
We can do the following activities to conserve water resources.
i. Plant more trees in barren lands.
ii. Plant trees near water resources.
iii. Do not throw garbage in water sources.
iv. Do not pollute the environment.

Only 3% of the total amount of water present on the earth is drinkable.
It is very hard to get enough of pure drinking water for all. So, we
must save water. Water should not be wasted.

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Some of the ways to save water are listed below:
i. Collect lots of clothes and wash them together.
ii. Close the tap when it is not in use.
iii. Use a wet towel to wipe face.
iv. Use a wet cloth to wash vehicles or clean tables.
v. Reuse the wastewater in the vegetable garden.
vi. Make a rainwater harvesting system at home.

close tap while brushing use wet towel to wash face use wet cloth to wash vehicles
fig: ways of saving water

Resonable facts
Why should we practise rainwater harvesting?

We should practise rainwater harvesting because it
helps us to save water.

Rainwater harvesting

Rainfall brings water. It is rainwater harvesting
absorbed by the soil. It also flows
into the river and lake. We can
harvest rainwater. The technology
of collecting rainwater in the tank
is called rainwater harvesting.
Rainwater falls on the roof. It is
collected into the tank with help
of a few tubes. This water can be
used in the garden, washing and
cleaning.

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Activity
Make a model of a rainwater harvesting technique.

Fact file
75% of the plant body is water.

Water cycle

Rain brings water. Water is absorbed by land. Some part of rain water

flows into rivers and ponds. During the day, heat energy from the

sun will heat up the water. Heated water changes into vapour. Vapour

rises up into the sky. It

will cool down and

change into tiny water

droplets. Millions of

water droplets will come

closer and change into

clouds. Cloud is carried

away by the wind. When

clouds become heavy, it

rains. It is called the

water cycle. The process water cycle

in which surface water

reaches the sky and rains down back to the Earth is called the water

cycle. It is the main source of water on land.

Fact file
The water cycle describes the flow of water throughout
the earth’s surface, atmosphere and underground.

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Activity
Make a model of the water cycle.

Hydropower

The energy present in moving water is called hydropower. It can be
used to rotate a turbine. The turbine can be connected to many devices.
It can be used to run a water mill and produce hydroelectricity.

Water mill

The water mill is a very old local technology. It water mill
contains a hut. The hut has two large round
stones. The stone at the top is connected to the
turbine. The turbine is placed in the path of water.
When water falls in the turbine, it rotates. The
rotating turbine rotates the stone. The grains are
crushed into powder.

Hydroelectricity

Hydroelectricity is a

modern technology. It

contains a turbine inside

the magnet. The turbine

is placed in the path of

the water. Water is

collected behind a dam.

When water flows down

the pipe, it rotates the technology of hydroelectricity
turbine. The rotating

turbine produces electricity. The electricity produced by rotating the

turbine with the help of flowing water is called hydroelectricity.

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Fact file
Hydroelectricity is a renewable source of energy.

Resonable facts
Why is hydroelectricity the best source of energy for
Nepal?
Hydroelectricity is the best source of energy for Nepal
because the country has many fast flowing rivers
where we can harvest electricity.

Water pollution

Is it safe to drink water from anywhere? No, it is not. Some sources
have fresh water. Some sources have salty water. Some sources have
dirty water. Water can dissolve other things. So, it may contain
harmful substances. The mixing of harmful substances in the water is
called water pollution.

Fact file
Chemical fertilisers pollute underground water.

Causes of water pollution

i. Mixing of garbage in water sources.

ii. Mixing of sewage from
hospitals and cities.

iii. Mixing of soil in water
sources during rainfall.

iv. Bathing and washing sewage dumping waste in water
clothes in the river. resources

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Effects of water pollution dead fish in dirty water dirty water contains germs

i. We will suffer from
many water borne
diseases.

ii. Fish and other aquatic
animals will die.

iii. Crops will be unhealthy
due to polluted water.

Preventive measures for water pollution:
i. Do not throw wastes in the water sources.
ii. Do not mix sewage in the river.
iii. Keep water sources clean.

Summary

1. The substances which have mass and volume are called matter.
2. The matter in which molecules are very close to each other is

called solid.
3. The matter in which molecules are very far from each other is

called gas.
4. The matter in which molecules are packed loosely than in solid

but are closer than in gas is called liquid.
5. Water is a matter because it has mass and volume.
6. The process in which liquid changes into vapour on heating is

called evaporation.
7. The process in which vapour changes into liquid on cooling is

called condensation.
8. The process in which liquid changes into solid on cooling is called

freezing.
9. The process in which solid changes into liquid on heating is called

melting.

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10. Water flows from a higher ground to a lower ground to maintain
its level.

11. The place that gives water is called the source of water.
12. Animals drink water from ponds and rivers directly.
13. We need water to wash our clothes and clean our house.
14. We should not throw garbage in water sources.
15. The technology of collecting rainwater in the tank is called

rainwater harvesting.
16. The process in which surface water reaches the sky and rains

down back to the earth is called the water cycle.
17. The energy present in moving water is hydropower.
18. The electricity produced by rotating the turbine with the help of

flowing water is called hydroelectricity.
19. The mixing of harmful substances in the water is called water

pollution.

Model Questions with Their Answer

1. Write the names of the solid forms of water.
Ice, snow, frost and hailstones are solid forms of water.

2. How much of the earth’s surface is covered by water?
About 71% of the earth’s surface is covered by water.

3. What happens when water is boiled?
Heating changes the state of matter. When water is boiled it will

change into vapour.

4. Why should we plant more trees near water sources?
We should plant more trees near water sources to prevent the

drying of water sources.

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5. What can you do to prevent water pollution in your village?
We can do the following things to prevent water pollution in our

village:
i. Raise public awareness.
ii. Not mix sewage in the river.
iii. Not throw garbage in the river.
iv. Not wash clothes in the river.

Exercise

1. Fill in the blanks with an appropriate word.

water matter liquid gas solid

a. The substances which have mass and volume are called
………

b. The matter in which molecules are very close to each other is
called ……….

c. The matter in which molecules are very far from each other
is called …………..

d. The matter in which molecules are packed loosely than the
solid but stronger than the gas is called ………….

e. All three forms of the matter is seen naturally in ………….

2. Write true for the correct and false for the incorrect statement.
a. The liquid form of water is present in lakes, ponds, rivers
and oceans.

b. Vapour is the solid form of water.
c. Snow, ice and hailstones are solid forms of water.
d. Water cannot change the state of the matter.
e. Water is colourless, odourless and tasteless.

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3. Choose the best answer from the given alternatives.

a. What is the process in which liquid changes into vapour?

Condensation Melting Evaporation Freezing

b. What is the process in which solid changes into liquid?

Melting Condensation Evaporation Solidification

c. What is the process in which vapour changes into liquid?

Evaporation Melting Condensation Freezing

d. What is the process in which liquid changes into solid?

Freezing Melting Evaporation Condensation

e. What is the process in which surface water travels to the sky
and rains down on the earth?

Condensation Water cycle Evaporation Melting

4. Match the following.

Ice no fixed shape

Solidification liquid change into vapour

Evaporation frozen water

Vapour liquid change into solid

Water gaseous form of water

5. Answer the following questions in a word each.
a. What is process called in which rainwater is collected in a
water tank?
b. What percentage of total amount of water is drinkable on
earth?
c. What is electricity produced from a rotating turbine with a
river called?

d. What when mixed in river pollutes water?
e. What is the source of energy for the water cycle?

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6. Write any two differences between:
a. Melting and solidification
b. Surface water and underground water

7. Give reason.
a. Water is called a matter.
b. Rainfall is important.
c. We should protect water resources.

8. Study the given diagram and answer the following questions.




i. Which natural process is shown in the diagram?
ii. What is the role of the sun in this process?
iii. What is the advantage of this process?
9. Answer the following questions.
a. Write any three uses of water in our daily life.
b. List at least three properties of water.

c. What is a source of water? Give an example of an underground
source of water.

d. What can be done to reduce the use of water?
e. What activities can protect water resources?
f. What is the importance of rainwater harvesting technology?

g. Describe the water cycle in brief.

10. Project work.

Use cotton and colours to make a model of the water cycle.

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Unit Air
6.2

Key terms and terminologies

1. Air: The mixture of gases present in the earth is called air.
2. Air pollution: The mixing of harmful gases, dust and germs in the air is

called air pollution.
3. Monsoon: The wind that brings rain in the lands is called the monsoon.
4. Air pressure: The property of air to push the wall of the container is called

air pressure.

5. Breeze: Gently moving wind is called breeze.

Introduction

Air is a matter. It has mass and occupies volume. It is a gaseous state
of matter. Its molecules are very far from each other. It can blow from
colder places to hotter places. Air is present on the earth. It is a mixture
of various gases. It contains 78% of nitrogen, 21 % of oxygen and
many other gases. The mixture of different gases present around the
earth is called air.

Properties of air

i. Air is an odourless, colourless and tasteless matter.

ii. We cannot smell, see or taste air because it does not have any

smell, colour and taste.

iii. It is present in the gas state.

iv. It has mass and weight.

Air is made up of molecules. It has mass. An

air-filled football is heavier than an empty one. air has mass

Fact file
Carbon dioxide can trap a large amount of heat energy.

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Activity
Measure the weight of an empty bicycle tube. Fill it
with air. Measure the weight again. What does it prove?

v. Air exerts pressure.
Air has weight. When air is filled in a bicycle tube, it pushes the

wall of the tube. The tube becomes strong and large. This is
because air is giving pressure from inside.

Activity
Air has pressure.
Find a tin can. Put some warm water in
the can. Close it. Put it in a refrigerator.
The can will be crushed. What does it
mean? Discuss in the group.

vi. It does not have a fixed shape and volume.
Air molecules are very loose. They fly from one place to another.

The air cannot maintain shape and volume. If we put a little air in
a large container, the air will expand and cover the entire
container.

vii. Air flows from colder places to hotter places.
Cold places have more air pressure than hot places. Therefore, air

flows from colder places to warmer places.

Fact file
Air blocks meteors.

Resonable facts
Why meteors don't hit the earth?
The meteors don’t hit the earth because the atmosphere
burns them.

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Uses of air

Air is very important component of the
environment. It is very useful in our daily life,
too. Some natural uses of air are listed below:
i. It helps plants in the pollination and air disperses feathery seeds

dispersal of seeds.
Air blows from colder places to warmer places. Moving air will

carry away pollen grains. Pollination will occur. Sometimes wind
carries away fuzzy seeds, too. Seeds will fall far away from the
plant and germinate there.
ii. It gives oxygen for respiration.
Air contains oxygen. It is used by plants and animals for
respiration. Respiration gives energy to our bodies.
iii. Plants take carbon dioxide from the air for photosynthesis.
Carbon dioxide is present in the air. The leaves of the plants
absorb carbon dioxide from the air. It is used in photosynthesis.
iv. Wind helps in the water cycle.
Wind helps to bring clouds over land. Monsoon brings rain from
the ocean upon land.

Humans also use air in many ways air pump fills air in tyres
wind mill
i. Air is filled in bicycle tubes and football.

Air gives pressure. This pressure makes
balls bouncy.

ii. Wind runs a wind mill.
Moving air has energy. This energy can

rotate the turbine. The rotating turbine
runs a wind mill. It is used to grind grains
or produce electricity.
iii. We can fly kites and balloons in the air.
iv. Oxygen helps in the burning of firewood.
v. Fan gives us cool air in the summer
season.

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Air pollution

Air is very important for life. It gives us oxygen to breathe. We must
breathe fresh air. The village has good air because there are many
trees. The city has dirty air because there is smoke from industries
and vehicles. There are fewer trees in the city. The mixing of harmful
gases, dust and germs in the air is called air pollution.

Some causes of air pollution are listed below:
i. Vehicles
Vehicles get energy from burning petroleum. They produce

smoke.
ii. Industries
Machines of industries often run on petroleum. Industries and

factories release smoke into the air.
iii. Cooking gas
People in the city cook food on the gas stove. Villagers use

firewood. Smoke is produced when burning fuel.
iv. Deforestation
The loss of trees increases the amount of carbon dioxide in the

air.
v. Degradable waste
Decaying waste material mixes bad smell in the air. Germs also

mix in the air.
vi. Storm
The storm will mix dust and sand in the air.

smoke from vehicles smoke from deforestation smoke from forest fire

industries
fig: causes of air pollution

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Fact file
The main causes of air pollution are petroleum and forest
fire.

Resonable facts
Why should we reduce the use of petroleum?
We should reduce the use of petroleum because
petroleum produces smoke.

Effects of air pollution are listed below:
i. People will suffer from lung diseases and heart diseases.
ii. It will burn eyes.
iii. Germs will spread diseases.
iv. Smoke and dust block the sky.
v. Plants do not grow well.

dust covers leaf and prevents polluted air damages lungs polluted air forms poisonous
photosynthesis fig: effects of air pollution smog

Control measures for air pollution:
i. Reduce the use of petroleum.
ii. Prevent forest fire.
iii. Filter dust and smoke from industries.
iv. Plant more trees.
v. Industries should be very far away from cities and villages.

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