Wonderful Weather - Experiment 3 1. Cloud in a bottle | 2. Tornado in a Bottle | 3. Air Pressure in a Jar | 4. Air Pressure on a glass| 5. Make a barometer | 6. Make a Thermometer Experiment: To lower the pressure in a jar, and observe its effects.
Materials:
You will need:
Water
What you have to do:
1) Place the candle in the centre of the saucer.
2) Pour some water into the saucer, to surround the candle. 3) Pour
three drops of food colouring into the water to improve its visibility.
4) Light the candle. 5) Carefully place the jar over the candle. 6)
Observe.
Result:
The coloured water disappears from the saucer as it is pushed into the
jar, while the heated air inside the jar escapes.
Conclusion:
The lit candle heats the molecules in the
air, causing them to move further apart - the air therefore expands and
some of it escapes from the jar as the water around it bubbles. When the
oxygen in the air in the jar is used up by the flame, the flame
extinguishes, causing the molecules to cool down. This causes the sudden
contraction of the air - the pressure in the jar is lowered. The higher
pressure outside forces the water to move up inside the jar
Sixth 1. Cloud in a bottle | 2. Tornado in a Bottle | 3. Air Pressure in a Jar | 4. Air Pressure on a glass| 5. Make a barometer | 6. Make a Thermometer | |||||
Method:
