The Candle Vacuum

Question:

How can you make water level in a glass jar rise?

Hypothesis:

By heating the air in the glass jar with a candle.

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Our Experiment

Materials: 

Picture
1. Candle
2. Small Piece of Modeling Clay
3. Tall Glass or Jar
4.  Round Glass Pie Plate
5.  Food Coloring
6.  Water
                            7.  Matches

Safety Procedures

Material 1: Do NOT Touch Candle Wick, or Hot Wax!
Material 3: Be Careful With Glass; Do NOT bang or Drop.
Material 5: Do NOT Eat.
Material 7: Be Extremely Cautious!

Procedure:

  1. Attach candle to pie plate with clay
  2. Fill jar with water and add food coloring
  3. Pour (1/2 in.) colored water from jar into plate
  4. Light candle and wait until flame is steady
  5. Hold jar over candle to heat-up air inside jar
  6. Lower jar onto pie plate gently
  7. Observe what happens to the candle and to the water level INSIDE the jar!!!
Special Needs:
Water, paper towels and fire extinguisher.

The Science behind it

The water level inside the glass jar rises because the burning candle heats the air inside the jar.
The air inside the jar now has a higher pressure than the air outside the jar.   The air ouside the jar is called "atmospheric pressure."  When the air in the jar cools, its pressure is lower than the atmospheric pressure outside the jar.  This creates a partial vacuum, which can not last for a long time!

The higher pressure of the air outside the jar pushes down on the water in the pie plate and forces it up into the jar.   


Conclusions

In conclusion we accept our hypothesis, because when the candle heats the air inside the jar, the pressure of the air inside jar also rises.  When this happens the high pressure outside the jar pushes down on the water in the pie plate and forces the water into the jar.  This is do to the partial vacuum.


Christopher Totoro

Mrs King's 5th Grade Class.
Plays piano & violin.
Plays soccer and loves football.
Likes hot spicy food.
Still deciding what he wants to do when he grows up.

Dominic Veltri

Mrs. Carvo's 5th Grade Class.
Plays piano & saxaphone.
Plays soccer, baseball & basketball ~ likes lacrosse.
Likes Italian food.
Wants to be a Lawyer.