The World of Things Chapter Notes | EVS Class 3: The World around us (Our Wondrous World) PDF Download

Introduction 

Explanation 

Let's Take a Look Around Us !

Khushi notices her classroom filled with various objects made of different materials. She wonders where they come from and what they are made of. Tables and chairs are made of wood, while door hinges, nails, and latches are made of metals. Metals are extracted from rocks and soil deep inside the Earth.

See-through Materials !   

1. See-Through: Transparent objects let light pass through them, so you can see what’s on the other side.

2. Clear: These objects are clear and don’t block your view.

Types of Materials 

Transparent: These materials allow light to pass through them clearly, so you can see through them easily. 

Example: Glass windows, Spectacles.

Translucent: These materials let some light through but not enough to see through them clearly.

Example: Frosted glass, thin plastic.

Opaque: These materials do not allow light to pass through, making it impossible to see through them.

Example: Wood, Book.

Does it Bend?  

Types of Materials

Flexible (Can Bend): These materials can be bent easily without breaking.

Example: Fabric, rubber. 

Rigid (Cannot Bend): These materials are hard and do not bend easily.

Example: Wood, metal. 

Does it Flow?

Flow describes how liquids, gases, and other things move. It means moving continuously and smoothly without stopping. 

Solids (Do Not Flow): Solids don't flow like liquids or gases. They keep their shape and don't move to fit a container. 

• Example: Wood, metal.

 2. Liquids (Flow): Liquids can flow easily. When you pour water into a cup, it moves smoothly and takes the shape of the cup. This is because liquids don't have a fixed shape and can flow to fit their container. 

• Example: Water, milk.

3. Gases (Flow Freely): Gases flows around us, filling any space it can find. It doesn't stay in one place like a liquid; instead, it moves freely and can spread out quickly. 

• Example: Air, helium. 

Natural - Artificial

Natural Materials: These are materials that occur in nature without human intervention. Examples include wood (from trees), metals (extracted from ores), and glass (made from sand). Natural materials can be living (like plants and animals) or non-living (like rocks, water, and air).Artificial Materials: These are materials created by humans. Examples include plastic (derived from petroleum), fabrics (like nylon and polyester), and metal alloys (like steel and brass). Artificial materials are used to make various everyday objects.

Understanding the different types of materials and their properties helps us appreciate the resources we use daily and make informed choices about how to use and manage them sustainably. This chapter encourages students to observe, question, and explore the materials around them to gain a deeper understanding of their world.

Points To Remember

1. Metals come from ores extracted from the Earth. -

2. Materials can be classified as transparent, opaque, or translucent based on how much light passes through them.

3.  Solid materials hold their shape, liquids flow, and gases spread out to fill their container. 

4. Natural materials exist in nature, while artificial materials are created by humans. 

5. Understanding the properties of materials helps us know what they can be used for. - Some materials, like rubber and wax, can be both natural and artificial. 

6. Observing changes in materials can provide insights into their characteristics and uses.

Difficult Words

1. Transparent: A material that you can see through clearly, like glass. 

2. Opaque: A material that you cannot see through, like wood. 

3. Translucent: A material that you can partially see through, like frosted glass. 

4. Materials: The substances used to make things, like wood or plastic. 

5. Alloys: Mixtures of two or more metals, like steel. -

6. Biodegradable: Materials that can break down naturally in the environment.