Trapping Water
You wil need:
Index/recipe card
Mason jar
Ring for the jar
Piece of screen
1. Fill the mason jar halfway with water.
2. Place a index card on top.
3. Gently place one hand on the card and one on the bottom and flip the jar over.
4. What will happen when you remove your hand.
How this works.
Air Pressure: We don't usually notice the air pressure around us. When you turn the cup upside down, the air pressure inside and outside the glass is equal, holding the card in place. The card stays until the paper becomes saturated or you tilt the glass and create an air pocket that releases the water.
But even more amazing...
1. Place screen on the jar and secure with the ring.
2. Fill the jar threw the screen.
3. Place index card on the top
4. Place one hand carefully on the top and one hand on the bottom and flip over.
What Happens?
5. Remove the index card.
What happens?
The Science:​
Surface tension is what keeps the water in the jar with just the screen holding it in place. Surface tension occurs when water molecules bond together across the tiny screen openings, forming a membrane-like barrier.
