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.
Hardness – Hard and Soft
Hardness is the property of a material that tells us how easily it can be scratched, pressed, cut, or changed in shape.
Hard Materials
Materials that are difficult to scratch, cut, press, or deform are called hard materials.
Examples:
Iron, Steel, Stone ,Glass, Wood , etc.
Soft Materials
Materials that can be easily pressed, scratched, cut, or changed in shape are called soft materials.
Examples:
Cotton, Sponge, Rubber, etc.
Transparency
Transparency is the property of a material that tells us how much light can pass through it.
Materials are mainly of three types:
A. Transparent Materials
Materials through which most or almost all light passes are called transparent materials.
Objects behind them can be seen clearly.
Examples:
Clear glass, Clean water, Air, Transparent plastic sheet
B. Translucent Materials
Materials through which some light can pass, but objects cannot be seen clearly, are called translucent materials.
Examples:
Butter paper, Frosted glass, Thin curtain, Oiled paper
Example: Light can pass through butter paper, but we cannot see objects clearly through it.
C. Opaque Materials
Materials through which light cannot pass are called opaque materials.
Objects behind them cannot be seen.
Examples:
Wood, Metal , Stone, etc.
Solubility in Water
Solubility is the ability of a substance to dissolve in a liquid, such as water.
Soluble Materials
Materials that dissolve in water are called soluble substances.
Examples:
Sugar, Salt, Some acids, Glucose , etc.
Insoluble Materials
Materials that do not dissolve in water are called insoluble substances.
Examples:
Sand, Chalk powder, Sawdust, Stones, etc.
Mass and Volume
Mass – Heavy and Light
What is Mass?
Mass is the amount of matter present in an object.
For example:
- A school bag has more mass than a pencil.
- A stone generally has more mass than a leaf.
We often use the words heavy and light to compare the mass of objects.
Units of Mass
The common units are: Gram (g), Kilogram (kg) , etc.
Examples
Pencil → about a few grams
Apple → about 100–200 g
School bag → a few kilograms
Rice bag → many kilograms
Measuring Mass
Mass is commonly measured using a balance or weighing machine.
Volume – Space Occupied
What is Volume?
Volume is the amount of space occupied by an object or substance.
For example:
A bottle occupies some space.
Water inside a glass occupies space.
A large box has greater volume than a small box.
Units of Volume
For liquids, we commonly use: Littre (L) , millilitre (mL) , etc.
Examples
- Medicine syrup → measured in mL
- Water bottle → measured in L or mL
- Bucket of water → usually measured in L
- Milk packet → commonly measured in L or mL
Mass VS Volume :-
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