Unit 1
Materials Around Us
You will learn about
* Natural
sources, man-made materials and things
* Matter - definition and properties
We use many
kinds of materials in our life. Nature is the source of all of them (e.g.,
tree). From these natural sources man makes many materials (e.g.,
wooden planks) which are used to make many other things (e.g., wooden basket).
Sources of Natural Materials
The sources of natural materials are plants,
animals, rocks and soil.
From Plants..
From Animals..
From Rocks and Soil...
We get metal ores from rocks
and soil
Think….
For today‛s need you are cutting me but
for tomorrow‛s need plant more trees like me…
Write ‘A‛
for the animal, ‘P‛ for the plant and ‘M‛ for the metal sources of the given materials.
Wood
Let Us Discuss
Why do we make windows and
cupboards from wood?
* Wood is a
strong material. So furniture can be made from it.
* It is long
lasting.
* It can be
cut into pieces and can be given different shapes.
* Wooden pieces
can be joined together to make many useful things
Natural source → Man-made
materials → Man-made things
Natural source
Man-made materials
Using some tools, tree trunks are cut into
wooden logs and planks.
Man-made things
Do you know?
Paper is made from wood
pulp.
Rubber
Do you know from what material
your eraser is made?
Rubber is made from the sap (a milky
substance) of the rubber tree.
* Rubber is elastic; so rubber bands are
made from it.
* It is also waterproof; so hand gloves
are made from it.
* Elastic – Comes back to its original
shape after being stretched
* Waterproof – Does not allow water to enter
inside
The following things are also made of rubber.
Observe the pictures and fill in the blanks.
Write
the names of the man-made things from wood.
1. Shelf 2. Spoon 3. Chair
Write
the names of the man-made things from rubber.
1. Rubber Band 2. Mat 3. Cycle Tube
Fibre
Do you know how clothes and
ropes are made?
Fibre is a material obtained from both
plants and animals. Cotton and jute are the fibres got from plants.
Wool and silk are fibres obtained from animals.
Fibre from the coconut tree is called coir. Many things are made from it.
Do you know? Silk thread is a strong material
and is used in making parachutes.
The jute fibre is long, shiny and
strong. Silk is the strongest natural fibre. We make many things like bags, mats and
sarees from these fibres.
Wool keeps us warm; so sweaters,
caps and socks are knitted using it.
Leather is flexible;
so belts, watch straps and bags are made from it.
Put a tick (✓) for the correct pair and a cross (x) for the wrong one.
Clay
Do you like playing with
clay?
* Clay is a natural material. It is a type
of soil. When it is mixed with water, it becomes soft.
* It hardens
as it dries; so, pots and other things can be made from it.
* A potter
uses his tool, the potter‛s wheel, to make clay pots and other things.
I give you cool water without using electricity.
Metals
Have
you seen the different vessels in your kitchen?
Metals are materials got from metal ores -
e.g., Gold, Silver, Iron and Copper.
* Since metals
are strong and hard, vehicles, gates and cooking vessels can be made
from it.
* Metals are
shiny.
* When heated,
metals can be shaped into any form - small paper clips or a huge aeroplane.
Matter
Anything natural
or man-made that occupies space is called matter.
Matter has
properties like taste, smell, size and shape.
Orange is a natural thing. It occupies space.
A wooden basket
is a man-made thing. It occupies space too.
These yellow laddus occupy the space in
the bowl.
They are small, round in shape and are sweet to taste.
Many materials
are used in making an object. Choose and write the correct pair of materials found
in the given objects.
1. Materials found
in motor bikes are _________ .
a. metals and clay
b. rubber and clay
c. metals and rubber
Ans
: c. metals and rubber
2. _________ are
found in these pots.
a. Clay and rubber
b. Metals and clay
c. Metals and rubber
Ans
: b. Metals and clay
3. This belt is made
of _________ .
a. fibre and rubber
b. metals and clay
c. metals and leather
Ans
: c. metals and leather
4. This chair is
made of _________.
a. metals and wood
b. fibre and rubber
c. metals and clay
Ans
: a. metals and wood
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