Question

Explain with an activity that air is necessary for combustion

Answer 1

When u light a candel and cover with a tall enough transparent glass (so that it does not touch the wick of the candel) u will see that the cancel starts flickering and it will we eventually put off.

Answer 2

fix a lighted candle on a table.put a glass chimney over the candle and rest it on a few wooden blocks in such a way that air can enter the chimney.observe what happens to the flame. now remove the blocks and let the chimney rest on the table.again observe the flame.finally put a glass plate over the chimney.watch the flame again.

hope its helpful