Water and Rocks Chapter Notes | Science Olympiad for Class 2 PDF Download

Water

• Water is a natural resource
• Water is required by humans, plants and animals to drink and live
• There is no fixed shape of water.
• Earth surface is covered by 71% of water.

Forms of water

1. Solid form of water

• A solid form of water is ice
• Ice is formed when water temperature is very low

2. Liquid form of water: Water is the liquid form of water.

3. Gas form of water: On heating, water gets converted into steam.
Water vapor forms cloud

4. Saltwater

• Very high amount of salt
• A major part of the earth is covered by salt water

5. Freshwater

• The concentration of dissolved salt is low
• Used for drinking
• Covers only 2% of the earth.

Uses of water

Rocks

• A hard matter which makes the mountains are called rocks
• Rocks have temples and carvings
• Rocks are found in different shapes, sizes and colours.

Types of Rocks

1. Granite

• Granite is a hard rock
• It is grey, black or light red in colour.
• Used in building houses, roads.

2. Marble

• It is a smooth rock
• Used to build statues, buildings.
• TajMahal is made of marble.

3. Sandstone

• It is a soft rock
• Can be broken into parts
• It is black in color

4. Graphite

• Black in color
• Used as lead in pencil

5. Slate

• It is a smooth rock
• Used for making slates and blackboards.

6. Limestone

• It is a soft rock
• Used in manufacturing of cement