JACKSON, Miss. (WJTV) – This experiment teach us about Atmospheric Pressure using a candle.
GRAB YOUR INGREDIENTS: a plate, a candle, a clear glass, a lighter, food coloring, and water
STEP 1: Add a few drops of food color into the glass of water
STEP 2: Pour the colored water into the plate until the surface is covered
STEP 3: Place the candle on the plate and carefully light it
NOTE: You’ll want adult supervision and help with this part and the next
STEP 4: Place the glass over the candle and watch what happens
Science behind this experiment: Heat is produced by the burning candle. When the cup is placed over the candle, the flame heats the air inside the glass, and the hot air expands quickly. When all of the oxygen is used up, the flame goes out.
At this point, there is low pressure inside the glass and high-pressure outside.
The change in air pressure pulls the water inside. Atmospheric pressure then tries to force it’s way in too. Because the water at the base of the cup has created an air tight seal, the pressure difference between the inside and outside of the cup causes the water to rise until the pressure inside the cup is equal to the pressure outside of the cup.