An iron nail is kept in each of the following liquids. In which case would it lose its shine and appear dull?

1

(a)

Mustard oil

(b)

Soft drink

(c)

Coconut oil

(d)

Kerosene

Which of the following materials is not lustrous?

1

(a)

Gold

(b)

Silver

(c)

Wood

(d)

Diamond

Which pair of substances among the following would float in a tumbler half-filled with water?

1

(a)

Cotton thread, thermocol

(b)

Feather, plastic ball

(c)

Pin, oil drops

(d)

Rubber band, coin

Find the odd one out from the following.

1

(a)

Tawa

(b)

Spade

(c)

Pressure cooker

(d)

Eraser

Sand is a material which is _____________  in water.

1

(a)

insoluble

Those materials through which we can see, are called __________ materials.

1

(a)

transparent

Dried leaves ______________ on the surface of water.

1

(a)

float

Vinegar dissolves in water.

1

(a) False

(b) True

Carbon dioxide gas is soluble in water.

1

(a) False

(b) True

Mustard oil is soluble in water.

1

(a) True

(b) False

Why a shopkeeper prefers to keep biscuits and sweets in a glass or plastic container?

2

(a)

Write the name of two objects which are made from opaque materials.

2

(a)

Do liquids dissolve in water?

2

(a)

Iron, steel, copper, aluminium are conductors of heat but wood, rubber, plastic, cotton piece are non-conductors. Explain.

3

(a)

Why are handles of utensils made from wood or plastics?

3

(a)

Our palm is translucent. Explain with an activity.

3

(a)

Why do you think oxygen dissolved in water is important for the survival of aquatic animals and plants.

5

(a)