Objective questions of chapter 1 based on matter of class 8.

 1. Write true or false for each statement:

A) The temperature of a substance remains unaffected during its change of state.

Ans.True.

B) ice melts at 100 degree Celsius.

Ans. False.

Ice melts at 0 degree Celsius.

C) water at hundred degree Celsius has more heat than steam at hundred degree Celsius.

Ans. False.

Water at hundred degree Celsius has less heat than steam at hundred degree Celsius.

D) evaporation of a liquid causes cooling.

Ans. True.

E) water evaporates only at hundred degree Celsius.

Ans. False.

Water evaporates at all temperatures.

F) boiling takes place at all temperatures.

Ans. False.

Boiling takes place at 100 degree Celsius.

G) evaporation takes place over the entire mass of the liquid.

Ans. False.

Evaporation takes place at the surface of liquid.

H) the process of a gas converting directly into solid is called the vaporization.

Ans. False.

The process of a gas converting directly into solid is called deposition or solidification.

I) at higher altitudes, water boils above 100 degree Celsius.

Ans. False.

At higher altitudes, water boils below 100 degree Celsius.

J) the melting point of ice is zero degree celsius.

Ans. True.

2. Fil in the blanks:

A) evaporation takes place at...all.... Temperatures.

B).. freezing..... Process is just the reverse of melting.

C)... Sublimation... Is a process that involves direct conversion of a solid into its vapour on heating.

D) the temperature at which a solid converts into a liquid is called its... Melting point....

E) the smallest unit of matter that exist freely in nature is called.. molecule......

F) molecules of a substance are always in a state of .... Random motion.... And so they possess. Kinetic energy.......

G) inter molecular space is maximum in... Gases....., less in... Liquids.... And the least in . Solids.....

H) intermolecular force of attraction is maximum in. Solids......., Less in.. liquids.... And the least in.. gases.......

3. Match the following:

A) molecules-  matter.

B) 100°C - water boils.

C) 0°C -  water freezes.

D) at all temperatures- evaporation.

E) camphor- changes from solid to gas.

4. Select the correct alternative:

A) the intermolecular force is maximum in:

1. Solids

2. Gases

3. Liquids

4. None of the above.

B) the intermolecular space is maximum in

1. Liquids

2. Solids

3. Gases

4. None of these.

C) the molecules can move freely anywhere in:

1. Gases

2.Liquids

3. Solids

4. None of the above.

D) the molecules move only within the boundary in :

1. Liquids

2. Gases

3. Solids

4. None of the above.

E)the temperature at which a liquid gets converted into its vapour state is called its:

1. Melting point

2. Boiling point

3. Dew point

4. Freezing point.

F) rapid conversion of water into steam is an example of:

1. Evaporation

2. Freezing

3. Melting

4. Vaporization.

G) evaporation takes place from the:

1. Surface of liquid

2. Throughout the liquid

3. Mid portion of the liquid

4. Bottom of liquid.

H) boiling takes place from:

1. The surface of the liquid

2. Throughout the liquid

3. mid portion of the liquid

4. None of the above.