Notes For All Chapters – General Science Class 6
Substances in Daily Use
1. Substances and Objects
Everything around us is made of substances.
Objects are made from different materials.
Example: A table can be made of wood, plastic, or metal.
2. Types of Substances
There are two main types of substances:
Natural Substances – Found in nature. Example: Cotton, wood, wool, metals, water, soil.
Man-made Substances – Made by humans. Example: Plastic, nylon, cement, glass.
3. Examples of Natural and Man-made Substances
| Natural Substances | Man-made Substances |
|---|---|
| Cotton (used for clothes) | Nylon (used for ropes and clothes) |
| Wood (used for furniture) | Plastic (used for bottles and bags) |
| Iron (used for construction) | Cement (used for buildings) |
4. Rubber
- Natural rubber is obtained from trees (sap called latex).
- Vulcanization: A process in which rubber is heated with sulphur to make it stronger.
- Used for tires, erasers, rubber bands, toys.
5. Paper
Paper is made from wood pulp (from trees).
Steps in paper-making:
- Remove bark from wood.
- Cut into small pieces and soak in water.
- Add chemicals to form pulp.
- Press and dry to make paper.
We should save paper to protect trees.
6. Fibres and Threads
- Natural Fibres: Cotton, wool, silk.
- Man-made Fibres: Nylon, polyester, rayon.
Types of Man-made Fibres
| Fibre | Uses |
|---|---|
| Nylon | Clothes, ropes, fishing nets |
| Rayon | Shiny clothes (also called synthetic silk) |
| Polyester (Terylene, Dacron) | Strong clothes, blankets |
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