Materials Around Us
You will learn about:
* Natural sources, man-made materials and things
* Matter - definition and properties
Introduction
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.
Activity: Fill in the Blanks
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.
Final Questions
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