Chapter-1


MATTER IN OUR SURROUNDINGS


1.    Convert the following temperatures to the celsius scale.

        (a) 293 K    (b) 470 K.


2.     Convert the following temperatures to the Kelvin scale. 


3.    Give reason for the following observations. 

    (a) Naphthalene balls disappear with time without leaving any         solid.

    (b) We can get the smell of perfume sitting several metres                  away. 


4.    Arrange the following substances in increasing order of               forces of attraction between the particles- Water, Sugar,               oxygen.


5.    What is the physical state of water at-
        (a) 25°C    (b) 0°C    (c) 100°C ?


6.    Give two reasons to justify-
        (a) Water at room temperature is a liquid. 
        (b) an iron almirah is a solid at room temperature. 

7.    Why is ice at 273 K more effective in cooling than water at            the same temperature?

8.    What produces more severe burns, boiling water of                       steam?

9.    Name A,B,C,D,E and F in the following diagram showing           change in its state 



      


Type- Bikash Bora