For safe extinguishing of an ampoule burner (Fig. 1 and 2) its flame is covered by a bigger glass container. In the following experiment you will explore how 2 candles behave under 2 jam jars of different sizes.
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         1              2                                      3                                                                    4
A3 Air is needed for burning. c . c .
Experiments with burners are only allowed if an adult is present

Material
Tray, 2 jams jars of different sizes, 2 candles, matches.
Experiment
1. Ignite the two candles inside a tray.
2. Simultaneously cover the burning candles with the jam jars.
3. Write down your observations.
Observations
Both candles go on burning for a short time (Fig. 3).
After few secondes the candle under the smaller container goes out (Fig. 4).
The candle under the larger container burns a little bid longer.
Explanation
The expiry happens as soon as the air covered by the jam jars is consumed. The larger one contains more of it.

back        first publication: 14.09.1998......... .last modification: 10.01.2011.