4.3 Additional Questions :
Answer the following questions :
1. What is the significance of the greenhouse gas ?
Ans: Without the greenhouse gas the earth would have been too cold to live in.
2. How does carbon dioxide create greenhouse gas ?
Ans: Carbon dioxide creates greenhouse effect by trapping the heat radiated from the earth.
3. What happens when air is heated ?
Ans: When air is heated, it expands , becomes lighter and goes up.
4. What is temperature ?
Ans: The degree of hotness and coldness of the air is known as temperature.
5. What is isolation ?
Ans: Isolation is the incoming solar energy intercepted by the earth.
6. How does air move ?
Ans: Air moves from high pressure areas to low pressure areas.
7. How do bacteria help plants use nitrogen ?
Ans: Bacteria that live in the soil and roots of some plants, take nitrogen from the air and change its form so that plants can use it.