What you need:
A tall glas
Petri dish (or any other plate, which is similar in design)
How the experiment works:
1. Place the coin in the petri dish/plate near the edge.
2. Place the tea light in the middle.
3. Fill the petri dish/plate with water (the coin must be covered).
4. Light the tea light and wait a moment until the tea light is burning properly.
5. Place the glass over the tea light and move the glass down.
What did you observe?
When the candle is lit, the air in the glass gets warmer. Warm air needs more space, which is why there is bubbling at the beginning. When the candle has used up all the oxygen in the air, the flame goes out and the air in the glass cools down. This creates a negative pressure and the water is pressed into the glass.