Page 2 - 2-HA-Practice Worksheet-1

d) Darjeeling.

7. Why does the water rise, when the candle is extinguished by 1 U
inverting a glass?
a) Because it has more air trapped inside the tumbler.
b) Because it has consumed all oxygen present in the jar.
c) Because it has consumed all carbon dioxide present in the jar
d) Because it has consumed all nitrogen present in the jar

8. Give reason:- 3 A
a) Traffic police wear a mask while controlling the traffic.
b) We can see water on the outer surface of the glass containing
chilled water.
c) We should breathe through our nose and not through the
mouth.
9. Answer the following. 3 U&A
a) Why does a balloon increase in size when we blow air in it?
b) Why should we plant more trees?
c) What will happen if we keep a fish in a closed container
without any aquatic plants?
10. a) What is the oxygen cycle? 5 R&U
b) How the balance of oxygen and carbon dioxide is maintained
in the atmosphere?
c) Draw the diagram for the above cycle.

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