Materials and Things

Q. Objects can be made of the same or different kind of materials. Explain with examples.

Q.

Question 24

Differentiate among opaque, translucent and transparent meterials, giving one example of each.

Q.

Out of the following options, which group of substances is made from the same material?

1. Switchboard, shirt, socks

2. Switchboard, chair, bench

3. Shirt, chair, pillow

4. Shirt, pillow, socks

Q. Chair can be made up of:

1. Wood
2. Rubber
3. Plastic
4. Iron

Q.

What are opaque bodies? Why are opaque bodies not called an opaque medium? Give four examples of opaque bodies.

Q. Which among the following are commonly used for making a safety pin?​

1. Wood and glass ​
2. Plastic and glass​
3. Leather and plastic ​
4. Steel and plastic​

Q.

How are objects classified on the basis of their transparency?

Q.

Why is it necessary to wash rice and pulses before cooking?

Q. Cricket ball is made of glass.

1. True
2. False

Q. Pick five objects from the word box given below which are opaque and would sink in water.

O	S	R	P	L	E
A	T	L	E	E	R
C	O	I	N	A	A
O	N	K	C	F	S
A	E	E	I	W	E
L	L	Y	L	R	R

Q. Select those objects from the following which shine: ​
Glass bowl, plastic toy, steel spoon, cotton shirt.​

Q.

Define translucent bodies with four examples:

Q.

Name the following:

A type of plastic that can be remoulded on heating.

Q.

2. Cardboard is translucent.

1. True
2. False

Q.

How thin is a thin film?

Q. Select the material that can be used to make a boat.

1. Marble
2. Wood
3. Rock
4. Glass

Q. (i) Given below are the names of some objects and materials:​
Water, basketball, orange, sugar, globe, apple and earthen pitcher​
Group them as: Round shaped and other shapes​

(ii) Given below are the names of some objects and materials:​
Water, basketball, orange, sugar, globe, apple and earthen pitcher​
Group them as: Eatables and non eatables​

Q.

If you can see the faint glow of a lighted torch through an object, but not the torch itself, is the substance opaque, translucent or transparent?

Q.

How do you classify plastics?

Q.

How are objects classified on the basis of their transparency?

Q. Which material is wrapped around the delicate items to prevent them from breaking?

1. Glass
2. Thermoplastics
3. Thermocol
4. Thermosets

Q.

A thin single glass plate is transparent. If the number of such glass plates are arranged in the form of a stack, is the arrangement will transparent? Explain.

Q. Match the objects given in Column I with the materials given in Column II.​

1. Plastics
2. Animale product
3. Steel
4. Plant product

Q.

Reuse is better than recycling of materials. Give reasons to justify this statement.

Q.

5 Which method is used for separating husk from grains?

Q. How can we classify objects based on their hardness?

Q.

Question 7

What will happen if....? And why?

(a) Nails are made of plastic.

(b) A bell is made of wood.

(c) Rubber is not fitted on a pair of tongs.

(d) A knife is made of wood.

(e) An axe is made of rubber.

Q.

Find the materials X and Y using which the listed products are made.

1. Paper, wood

2. Metal, glass

3. Plastic, metal

4. Cotton, paper

Q.

Some objects and some materials are listed below. Match the object with the material it is usually made of.

Object		Material
Ornaments		Plastic
Aquarium		Cotton
Tables		Metal
Sleeping matress		Wood
Water bottles		Glass

Q.

Question 7

What will happen if....? And why?

(a) Nails are made of plastic.

(b) A bell is made of wood.

(c) Rubber is not fitted on a pair of tongs.

(d) A knife is made of wood.

(e) An axe is made of rubber.