Page 3 - CBW
P. 3

12.    Observe the picture given, and answer the following
                    questions:

                       a)  What is the significance of carbon dioxide in the
                           atmosphere?
                       b)  What is the role of nitrogen in the atmosphere?
                       c)  How does water vapor affect the atmosphere?



             13.    Activity:
                    A student places a glass jar over a burning candle. She notices
                    that a candle flame extinguishes after sometime.

                    Question:
                    Why does the candle flame go out when covered with a glass
                    jar?


             14.       a)  Explain how animals living underwater are able to
                           respire?

                       b)  What will happen to this when the water is heated?






             15.       a)  Describe why the balance of oxygen in the environment is essential for the survival of
                           humans and animals.
                       b)  How is the balance of oxygen and carbon dioxide maintained in the air?
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