Question

in one word:
1. What happens to natural gas when it is burnt?
2. Name the phenomenon of burning a substance in
the presence of oxygen.
3. What type of combustion takes place when the
food you've eaten is used to provide energy for your
IX
1.
body?
4. Which zone of a flame is the hottest zone?
5. Name the fuel being used at home for cooking
food.
6. When a substance catches fire, what is that
temperature known as?
7. The efficiency of a fuel is determined in which
terms?
8. Name the substance which is burnt to use its heat
energy?
VII. Answer the following questions in brief:
1. Why it is harmful to sleep in a closed room where
coal fire is burning?
2. What are the three important requirements to
initiate fire?
3. What happens to the wax when a candle is burnt? Is
it possible to recover this wax back?
4. State any two reasons why a particular fuel is
considered to be the best.
5. Define calorific value of a fuel.
6. What do the letters L.P.G. stand for?
7. Mention any two cost-effective ways of cooking.
8. How does a fire extinguisher extinguish fire?​

Answer 1

I don't know this answer but please mark me as brainliest