Objectives

To demonstrate how air pressure can defy gravity

Materials

• Plastic bottle (12-20 oz) filled with water
• Bucket or bowl
• Index or playing card

Procedure

Fill the bottle to the rim with water. Hold the bottle over a bucket, bowl, or sink in one hand. Using the other hand, place the card firmly over the mouth of the bottle of water. Turn the bottle upside down. Carefully remove your hand. 

Conclusion

The card stays in place and the water stays in the bottle. The force of air pressure is pushing up on the card harder than the force of gravity is pushing down on the water. The card creates a seal. When the card comes off,  prepare to be amazed!