Question

1. Why some substances burn with a flame while some burn
without a flame?
2. List conditions under which combustion can take place.
Or
What are the conditions necessary for combustion to take place?
3. Why is it necessary to wrap a person in a thick blanket whose
clothes have caught fire?
4. Abida and Ramesh were doing an experiment in which water has
to be heated in a beaker. Abida kept the beaker near the wick in
the yellow part of the candle flame. Ramesh kept the beaker in
the outermost part of the flame. Whose water will get heated fast
and why?
5. Can the process of rusting be called combustion? Discuss.
6. What are the characteristics of an ideal fuel?
7. What is acid rain? How is acid rain harmful?
8. If a can full of kerosene catches fire, what is the simplest way to
put off this fire?
9. What is explosive combustion? Give one example.
10. What are inflammable substances? Give examples.
11. Draw a well labelled diagram of a candle flame.
12. What are the harmful effects of burning fuels?
13. Write an activity to show that oxygen is necessary for
combustion.
14. Water is not used to control fires involving electrical equipment.
Give reason.
15. Compare LPG and wood as fuels.​

Answer 1

Answer:

2 . Ans .Three things are required in proper combustion before ignition and combustion can take place heat ,oxygen and fuel Their must be fuel to burn their must be air to supply oxygen their must be heat (ignition temperature ) to star and continue the process of combustion.