How will you show that air supports burning?

Hint: Air is a mixture of seventy eight percent nitrogen and twenty one percent oxygen with some traces of carbon dioxide, water vapors and some other gases.

Complete step by step answer:
In order to prove that air supports burning we need to do a very simple experiment which can be done easily by anyone.
Just take two candles and place them on a table. After that lit both the candles and we will see that both of them will be kept on burning in the atmosphere.
Now what we have to do is cover the first burning candle with an inverted glass jar, glass jar is taken because it is transparent so that we can see what's happening inside the jar, after covering it we will notice that the candle will stop glowing it will be extinguished after some time whereas the other candle continues to burn.
So this concludes that as we covered the candle the supply of air is stopped therefore the candle stopped burning it means that air is required for the candle to burn.

Hence this simple experiment proves that air supports burning.

Note:
Air is a mixture of gases, which contains 78% of nitrogen and 21% of oxygen with traces of water vapor, carbon dioxide, argon, and various other components. Pressure and temperature of the air varies from place to place on the earth. Pressure and temperature change day to day, hour to hour, sometimes even minute to minute during several weather conditions. The gravity of the Earth holds the atmosphere to the surface, as the altitude increases, the air density, the pressure, and temperature also decrease.