Hey I can tell this with the help of an experiment,
Take a candle and burn it.
Keep it burning for 2-3 mins.
Then Keep a beaker or a transparent glass on top of the candle
You will observe that just after a few seconds,the candle will stop burning and this experiment tells us that burning of a substance can occur only in air and not in vaccum
please give it the best answer i need to go to the next rank