To observe that fire needs oxygen to burn
- Three votive candles that are the same size
- Large clear drinking glass (approximately sixteen ounces)
- Small clear drinking glass (eight ounce)
- Matches or lighter
Light the candles and put the glasses over two of the candles simultaneously. Do not put a glass over the third candle. Watch to see which candle burns out first.
Fire needs oxygen to burn. The candle that has unlimited oxygen will burn for a long time. The candle in the smallest glass will go out before the candle in the large glass because there is less oxygen in the small glass.