Questions with Answers

Matter and Materials ( Term 1 Chapter 2 | 4th Science )

Evaluation

I Find the odd one.

1. brick, coir, silk cloth, pine apple

Answer: silk cloth

2. stone, rubber band, cycle tube, electric wire

Answer: stone

3. sun, candle, torch, pen

Answer: pen

4. umbrella, sponge, rain coat, jerkin

Answer: sponge

5. glass bottle, exam pad, paper plate, wooden board

Answer: glass bottle

II Fill in the blanks.

1. Materials which can be compressed or cut easily are called soft materials.

2. Gold and diamond are the examples of shiny materials.

3. Materials which can be bent or stretched easily are called flexible materials.

4. Transparent objects allow all the light to pass through them.

5. Light is the natural source that stimulates sight and makes things visible.

III Match the following.

1. Light source - Glass

2. Waterproof - Vegetable oil

3. Transparent - Sun

4. Translucent - Metal

5. Opaque - Rain coat

Answer:

1. Light source - Sun

2. Waterproof - Rain coat

3. Transparent - Glass

4. Translucent - Vegetable oil

5. Opaque - Metal

IV Say True or False.

1. We cannot compress, cut or bend the rough materials easily. (True)

2. Dull materials reflect light. (False)

3. Sand paper is a good example for smooth materials. (False)

4. Opaque objects do not allow light to pass through them. (True)

5. Mirrors change the direction of light that fall on them. (True)

V Answer the following.

1. When can you say a material is waterproof material?

Materials that do not allow water to pass through them are called Waterproof Materials.

Example : Raincoat and aluminium foil of tablet strip.

2. What is a light source?

The objects that give off light are called light sources.

3. What is the difference between transparent and opaque materials?

Transparent objects allow the light to pass through them. Opaque objects do not allow light to pass through them.

4. Define reflection.

The bouncing of light by any smooth or polished surface is called reflection.

5. Classify the objects given below as transparent, translucent or opaque materials.

(Air, Rock, Water, Aluminium foil, Mirror, Snow, Wooden board, Polythene bag, CD, Oil soaked paper, Glass tumbler and Coloured glass)

Transparent Materials : Air, Glass tumbler, Water

Translucent Materials : Snow, Polythene bags, Oil soaked paper, Coloured glass

Opaque Materials : Rock, Aluminium foil, CD, Wooden board, Mirror

VI Projects

Collect some rough and smooth materials from your surrounding.

Try to Answer

Look at the pictures and identify the materials by which they are made of:

(paper, clay, glass, wood, plastic, metal rubber, wax)

Try to Answer

Match the objects that are made of same material.

Answer: Plastic material, Wooden material, Leather material

Try to Answer

Write whether the given materials are hard or soft.

Try to Answer

Collect some objects from your house and classify them as shiny or dull materials.

Try to Answer

Sort the given objects as rough or smooth.

Activity

Test the flexibility. 

Give one plastic scale and wooden scale to the students. Ask them to bend. Tabulate their observation (bends, does not bend).

Think and answer

Do you have a raincoat? What is its use?

Activity

Take a glass bowl. Fill three fourth of it with water. Put an orange fruit with peel and an orange fruit without peel. Observe which orange floats? Why?

Answer: Orange with peel floats because it is waterproof. Orange without peel sinks because water gets into it and makes it heavy.

Activity

Complete the Worksheet

Name : Class :

Date : Unit : 2. Matter and Materials

Complete the sentence in you own words.

1. Transparent objects allow light to pass through them.

2. Translucent objects allow some light to pass through them.

3. Opaque objects allow no light to pass through them.

Try to Answer

Write whether the objects are transparent, translucent or opaque.

Try to Answer

Try to see your face on some materials like mirror, exam pad, new stainless steel plate, table top and water in a plate. What are the materials that show your face clearly? Do you know why?

Answer: Mirror and new stainless steel plate show my face clearly. This is because their polished surface reflects light.

Activity

Reflection of Light

Material Required/Needed

A plane mirror and a torch light

How to do?

1. Make your room dark by closing the door and windows.

2. Ask your friend to hold a mirror in his/her hand at one corner of the room.

3. Stand at another corner with a torch in your hand.

4. Switch it on.

5. Direct the light from the torch onto the mirror.

6. Answer the following from your observation:

a) When you change the angle of the mirror, what happens to the light?

Answer: The angle of reflection also changes when we change the angle of the mirror.

b) Are you able to direct the reflected light using the mirror?

Answer: Yes, I am able to direct the reflected light using the mirror.