Page 88 - ICSE Science 3 : E-book

TIME TO REVISE

Write (T) for true or (F) for false statements.

1. Gases are invisible but essential for us.

2. Water is the most important gas on earth.
3. Water is known to exist in three diff erent forms.

4. We use CNG as fuel in our vehicles.

5. The food we eat is solid.

Diff erent Forms of Water

Water is mainly known to exist in its three diff erent forms—solid

(ice), liquid (water) and gas (water vapour). Water can change
from one form to another because of temperature changes.

This occurs through a simple process of heating or cooling.

TERMS TO KNOW

1. Mass: The quantity that tells how heavy or light an object is

2. Matter: Anything that has mass and occupies space
3. Solids: Substances that are usually hard, and have a fi xed shape and size

4. Liquids: Substances that do not have a fi xed shape or size, and fl ow easily
5. Gases: Substances that are usually invisible, and do not have a fi xed shape or size

QUICK LOOK

1. All the things around us share common features like mass and space.

2. Everything around us is matter. It includes both living and non-living things.
3. Matter exists in three diff erent forms. They are solids, liquids and gases.

4. Each form of matter has diff erent properties.
5. Solids, liquids and gases are used for various purposes in our daily lives.
6. All forms of matter are important for our living.

7. Water is mainly known to exists in three diff erent forms.

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