SORTING MATERIALS INTO GROUPS

A

100

I am the 20th element.

Calcium

200

Why are most of the balloons, tyres and footballs made of rubber?

A)  It is naturally available.

B)  It is cheap.

C)  It is an electrical insulator.

D)  It is soft and flexible.

D)  It is soft and flexible.

300

Which of the following statements is correct?

A)  Only some hard substances sink.

B)  All soft objects can be torn easily.

C)  All soft objects float in water.

D)  Some soft substances sink.

All soft objects can be torn easily.

400

a) A: Iron is an opaque material.

R:) We are unable to see things through iron.

I.) Both A and R are true and R is the correct explanation of A.

II.) Both A and R are true but R is not the correct explanation of A.

III.) A is true but R is false.

IV.) A is false but R is true.

I

500

GIVE REASONS FOR THE FOLLOWING: 

1. Tumbler is not made up of cloth.

Tumbler is used to hold water, so if it is made with cloth, it cannot hold water as the cloth will get wet and the water will leak.

B

100

I combine with Carbon to form a gas you breathe out.

Oxygen

200

If opacity is the distinct feature of wood, then what is glass known for in the same way?

A)  Its transparency

B)  Its magnetic nature

C)  Its conductivity to heat

D)  Its lustrous nature

A)  Its transparency

300

Equal volumes of oil and water are taken in two glasses and weighed.  What is the likely outcome?

A)  Oil weighs more.

B)  Water weighs more.

C)  Both oil and water weigh the same.

D)  Water weighs less when heated.

B)  Water weighs more.

400

 A: Salt is called insoluble substance.

R: Salt disappears completely in water.

I.) Both A and R are true and R is the correct explanation of A.

II.) Both A and R are true but R is not the correct explanation of A.

III.) A is true but R is false.

IV.) A is false but R is true.

IV

500

1. Handles of utensils are made of plastic or wood.

1. Plastic and wood are bad conductor of heat, so it will prevent the hand from burning while cooking.

C

100

Which is the position of scandium in the periodic table?

21

200

Even though a cinema hall is a place prone to fire hazards, the interiors are mostly made up of wooden panels. Why is this so?

A)  It does not catch fire easily.

B)  It is opaque.

C)  It absorbs sound.

D)  It is very commonly available.

C)  It absorbs sound.

300

Why are overhead cables not insulated?

A)  Because air is a bad conductor of electricity.

B)  Because air is a good conductor of electricity.

C)  Bare wires conduct electricity better.

D)  Both (b) and (c).

 Because air is a bad conductor of electricity.

400

Assertion : On the basis of transparency, materials can be grouped as transparent, translucent and opaque.
Reason : Oiled paper is translucent.

A If both assertion and reason are true and reason is the correct explanation of assertion.

B If both assertion and reason are true but reason is not the correct explanation of assertion.

C If assertion is true but reason is false.

D If assertion is false and reason is true

B

500

Kerosene, coconut oil, mustard oil do not dissolve in water, even on shaking. They separate after sometime forming two different layer. Explain why.

The molecules of water do not intermingle (mix) with the molecules of oil. The space between the molecules of water is not taken by oil, so they are immiscible in water.

D

100

My symbol comes from the Latin name and I come after Argon.

Potassium

200

Which of the following is true of pure water?

A)  A good conductor of electricity

B)  A bad conductor of electricity

C)  A semiconductor

D)  A superconductor

A bad conductor of electricity

300

We group the materials for our convenience and also for some other reasons. Materials are grouped together on the basis of

A) similarities in their properties

B) differences in their properties

C) both on similarities and difference in their properties

D) None of the above is correct

c

400

Assertion A: Wood is a good conductor of heat. Reason R: Substances which do not allow heat to pass through them are called poor conductors of heat.

A) Both A and R are true and R is the correct explanation of A.

B) Both A and R are true but R is not the correct explanation of A.

C) A is true but R is false.

D) A is false but R is true.

D

500

Why some shining materials eventually loose their shine and appear dull in due course of time? Is the loss of shine permanent?

Shining materials which can react with oxygen and moisture in the air forms a coating of dull layer on their surface.
No, it’s not permanent. It can be reversed by polishing the surface.

E

100

I am found mostly in your body.

Calcium

200

Which of the following type of bodies form sharp shadows when placed in the path of light?                        

A)  Transparent      

B)  Translucent        

C)  Transparent and translucent        

D)  Opaque      

Opaque    

300

Which of the following is the characteristic of materials with lustre

A) Their lustre can be seen when it is freshly cut

B) Their lustre can be seen when it is rubbed with sand paper

C) Both (a) and (b)

D) None of the above

C

400

(i) Vinegar forms a separate layer when mixed with water. (ii) Chalk that we use to write en black board dissolves in water and is soluble substance.

A) Statement (i) is correct while statement (ii) is incorrect.

B) Statement (i) is incorrect while statement (ii) is correct.

C) Both option are correct

D) Both option are incorrect.

D

500

Ramesh has three glass windows in his study room. He painted one of his glass window pane with yellow colour, the other one with black and he left the third one as it is.

1. Through which window pane can he see the outside clearly?
2. Through which window he will not be able to see at all?
3. What will happen when he views outside through the yellow window pane.

1. The one without any paint as it is transparent.
2. The window he painted black as it is opaque.
3. He will everything clearly but yellow in colour as it is translucent.