Materials – Definition and Examples
A material is a substance from which an object is made.
We use different materials to make different objects because materials have different properties.
Example :- Chair made of plastic, Wood , metal etc .
Glass made of glass.
Earliest Pottery
Pottery is one of the earliest examples of objects made by humans using natural materials.
Harappan Civilisation
The people of the Harappan Civilisation used clay to make different objects such as:
Pots, Bowls, Toys, Storage containers, Decorative objects etc.
The clay objects were heated at high temperatures to make them hard and durable.
Terracotta
Terracotta means baked clay.
The word comes from Italian:
Terra = Earth
Cotta = Baked
So, terracotta = baked earth/clay.
Harappan people made many beautiful terracotta objects, including toys, figurines and pottery.
Classification of Materials – Grouping
There are many different materials around us. Studying each material separately can be difficult.
So, we group materials according to their common properties.
This process is called classification or grouping of materials.
Why do we group materials?
Grouping helps us:
- Study materials easily.
- Understand their properties.
- Compare different materials.
- Choose the right material for a particular object.
Example
We can group objects according to the material they are made from:
Metal group:
Iron, copper, aluminium, gold
Wood group:
Wooden chair, wooden table, wooden door
Plastic group:
Plastic bottle, plastic bucket, plastic toy
Glass group:
Glass tumbler, window glass, glass bottle
Appearance – Lustrous and Non-Lustrous
The appearance of a material means how it looks, especially whether its surface has a shine or not.
Based on appearance, materials can be classified as:
A. Lustrous Materials
Materials that have a shiny or glossy surface are called lustrous materials.
Examples:
Gold, Silver, Copper, Aluminium, Iron (when polished) ,etc.
Lustre = Shine
B. Non-Lustrous Materials
Materials that do not have a shiny surface are called non-lustrous materials.
Examples:
Wood, Paper, Cotton, Rubber, Clay etc.
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