CLASS 9
SCIENCE WORKSHEET

HOLIDAY  HOMEWORK (2019-20)

SUBJECT –SCIENCE(chemistry)

CLASS IX

Chapter 1 - Matter In Our Surroundings

I Choose the best correct option in the following questions

 : Q.1. Which of the following changes represent sublimation?

(a) solid  liquid (b) solid  gas (c) liquid  gas (d) gas  liquid

Q.2. Gases do not have–

 (a) high compressibility (b) high fluidity (c) high density (d) large volume

 Q.3. Evaporation

 (a) takes place below melting point (b) is a bulk phenomenon (c) takes place above boiling point (d) is surface phenomenon

Q.4. Particles of a liquid–

 (a) are most ordered (b) move randomly (c) have large intermolecular spaces (d) can slip and slide over each other

 Q.5. Which of the following pairs will not exhibit diffusion?

 (a) hydrogen, oxygen (b) oxygen, water (c) salt, sand (d) sugar, water

Q.6. Which of the following is not a property of solids

(a) fixed shape and volume (b) interparticle spaces are minimum (c) Particles can move freely within a limited space (d) Forces of attraction between the particles are maximum

 Q.7. The solid that would sublime on heating is

(a) wax (b) solid carbon dioxide (c) ice (d) butter

Q.8. A substance melts at -250 C and boils at 850 C, Which of the following statements about it is correct?

(a) It would be in solid state at -150C (b) It would be in gaseous state at -900C (c) It would be in liquid state at -250C (d) It can in liquid state or in gaseous state at -850C

 Q.9. Melting points of four solids A, B, C and D are 780 C, 2620 C, 1000 C and 1680 C

 Inter particle forces of attraction are in the order

 (a) A>C>D>B (b) B>C>D>A (c) A>D>C>B (d) B>D>C>A

II   S    study  the     figure            given below            for      inter  conversion  of particles of     of   states  of           matter          carefully       and     answer          the     questions tha     that follow:

Q.1. Name the process marked as A,B,C,D

. _____________________________________________________________________

Q.2. To which state of matter a liquid changes on increasing its temperature? ______________________________________________________________________________

 Q.3. What change do we expect on increasing pressure and lowering temperature of a gas? ______________________________________________________________________________

 Q.4. When a liquid is cooled, it may change into a new state of matter. Name that state. ______________________________________________________________________________

Q.5. What is sublimation? ______________________________________________________________________________

III      Temperature can be measured in two different scales - °C and Kelvin (K)

The SI unit of temperature is Kelvin            

K =°C  + 273

 °C = K – 273   

Q.1. Convert the following temperature to the celsius scale. a. 470 K         b. 300 K          c. 298 K          

Q.2. Convert the following temperature to the Kelvin scale. a. 25°C     b. 373°C    c. 273°C 

Q3 A  sample of water was heated from 25°C to 30°C.

 (a) What were the initial and final temperatures of water in Kelvin scale?

 (b) How much was the rise in temperature on Celsius scale?

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